Method and Apparatus for Signal Processing and Encoding and Decoding Method, and Apparatus Therefor

ABSTRACT

An apparatus for processing a signal and method thereof are disclosed. Data coding and entropy coding are performed with interconnection, and grouping is used to enhance coding efficiency. The present invention includes the steps of obtaining a pilot reference value corresponding to a plurality of data and a pilot difference value corresponding to the pilot reference value and obtaining the data using the pilot reference value and the pilot difference value.

TECHNICAL FIELD

The present invention relates to an apparatus for processing a signaland method thereof, and more particularly, to an apparatus for codingdata and method thereof.

BACKGROUND ART

Generally, many techniques for signal compression and recovery have beenintroduced so far. And, applicable targets of the correspondingtechniques are various data including audio data, video data and thelike. Moreover, the signal compression or recovery techniques evolve ina direction to enhancing audio or video quality with high compressionrates. Besides, many efforts have been made to raise transmissionefficiency for adaptation to various communication environments.

However, it is still believed that there exists a margin for theenhancement of the transmission efficiency. So, many efforts need to bemade to maximize transmission efficiency of signals in the verycomplicated communication environments through the development of newprocessing schemes for signals.

DISCLOSURE OF THE INVENTION

Accordingly, the present invention is directed to an apparatus forprocessing a signal and method thereof that substantially obviate one ormore of the problems due to limitations and disadvantages of the relatedart.

An object of the present invention is to provide an apparatus forprocessing a signal and method thereof, by which transmission efficiencyof signals can be optimized.

Another object of the present invention is to provide an apparatus forcoding data and method thereof, by which data can be efficiently coded.

Another object of the present invention is to provide an apparatus forencoding/decoding data and method thereof, by which transmissionefficiency of control data used for audio recovery can be maximized.

Another object of the present invention is to provide a medium includingencoded data.

Another object of the present invention is to provide a data structure,by which encoded data can be efficiently transferred.

A further object of the present invention is to provide a systemincluding the decoding apparatus.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a method ofprocessing a signal according to the present invention includes thesteps of obtaining a pilot reference value corresponding to a pluralityof data and a pilot difference value corresponding to the pilotreference value and obtaining the data using the pilot reference valueand the pilot difference value. The method further includes the step ofdecoding at least one of the pilot reference value and the pilotdifference value. And the data are parameters and the method furtherincludes the step of reconstructing an audio signal using the obtainedparameters.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, an apparatus for processing a signalincludes a value obtaining part obtaining a pilot reference valuecorresponding to a plurality of data and a pilot difference valuecorresponding to the pilot reference value and a data obtaining partobtaining the data using the pilot reference value and the pilotdifference value.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a method of processing a signalincludes the steps of generating a pilot difference value using a pilotreference value corresponding to a plurality of data and the data andtransferring the generated pilot difference value.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, an apparatus for processing a signalincludes a value generating part generating a pilot difference valueusing a pilot reference value corresponding to a plurality of data andthe data and an outputting part transferring the generated pilotdifference value.

ADVANTAGEOUS EFFECTS

Accordingly, the present invention enables efficient data coding andentropy coding, thereby enabling data compression and recovery with hightransmission efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 are block diagrams of a system according to thepresent invention;

FIG. 3 and FIG. 4 are diagrams to explain PBC coding according to thepresent invention;

FIG. 5 is a diagram to explain types of DIFF coding according to thepresent invention;

FIGS. 6 to 8 are diagrams of examples to which DIFF coding scheme isapplied;

FIG. 9 is a block diagram to explain a relation in selecting one of atleast three coding schemes according to the present invention;

FIG. 10 is a block diagram to explain a relation in selecting one of atleast three coding schemes according to a related art;

FIG. 11 and FIG. 12 are flowcharts for the data coding selecting schemeaccording to the present invention, respectively;

FIG. 13 is a diagram to explaining internal grouping according to thepresent invention;

FIG. 14 is a diagram to explaining external grouping according to thepresent invention;

FIG. 15 is a diagram to explain multiple grouping according to thepresent invention;

FIG. 16 and FIG. 17 are diagrams to explain mixed grouping according toanother embodiments of the present invention, respectively;

FIG. 18 is an exemplary diagram of 1D and 2D entropy table according tothe present invention;

FIG. 19 is an exemplary diagram of two methods for 2D entropy codingaccording to the present invention;

FIG. 20 is a diagram of entropy coding scheme for PBC coding resultaccording to the present invention;

FIG. 21 is a diagram of entropy coding scheme for DIFF coding resultaccording to the present invention;

FIG. 22 is a diagram to explain a method of selecting an entropy tableaccording to the present invention;

FIG. 23 is a hierarchical diagram of a data structure according to thepresent invention;

FIG. 24 is a block diagram of an apparatus for audio compression andrecovery according to one embodiment of the present invention;

FIG. 25 is a detailed block diagram of a spatial information encodingpart according to one embodiment of the present invention; and

FIG. 26 is a detailed block diagram of a spatial information decodingpart according to one embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

General terminologies used currently and globally are selected asterminologies used in the present invention. And, there areterminologies arbitrarily selected by the applicant for special cases,for which detailed meanings are explained in detail in the descriptionof the preferred embodiments of the present invention. Hence, thepresent invention should be understood not with the names of theterminologies but with the meanings of the terminologies.

In the present invention, a meaning of ‘coding’ includes an encodingprocess and a decoding process. Yet, it is apparent to those skilled inthe art that a specific coding process is applicable to an encoding ordecoding process only, which will be discriminated in the followingdescription of a corresponding part. And, the ‘coding’ can be named‘codec’ as well.

In the present invention, steps of coding a signal shall be explained bybeing divided into data coding and entropy coding. Yet, correlationexits between the data coding and the entropy coding, which shall beexplained in detail later.

In the present invention, various methods of grouping data toefficiently perform data coding and entropy coding shall be explained. Agrouping method has independently effective technical idea regardless ofspecific data or entropy coding schemes.

In the present invention, an audio coding scheme (e.g., ‘ISO/IEC 23003,MPEG Surround’) having spatial information will be explained as adetailed example that adopts data coding and entropy coding.

FIG. 1 and FIG. 2 are diagrams of a system according to the presentinvention. FIG. 1 shows an encoding apparatus 1 and FIG. 2 shows adecoding apparatus 2.

Referring to FIG. 1, an encoding apparatus 1 according to the presentinvention includes at least one of a data grouping part 10, a first dataencoding part 20, a second data encoding part 31, a third data encodingpart 32, an entropy encoding part 40 and a bitstream multiplexing part50.

Optionally, the second and third data encoding parts 31 and 32 can beintegrated into one data encoding part 30. For instance, variable lengthencoding is performed on data encoded by the second and third dataencoding parts 31 and 32 by the entropy encoding part 40. The aboveelements are explained in detail as follows.

The data grouping part 10 binds input signals by a prescribed unit toenhance data processing efficiency.

For instance, the data grouping part 10 discriminates data according todata types. And, the discriminated data is encoded by one of the dataencoding parts 20, 31 and 32. The data grouping part 10 discriminatessome of data into at least one group for the data processing efficiency.And, the grouped data is encoded by one of the data encoding parts 20,31 and 32. Besides, a grouping method according to the presentinvention, in which operations of the data grouping part 10 areincluded, shall be explained in detail with reference to FIGS. 13 to 17later.

Each of the data encoding parts 20, 31 and 32 encodes input dataaccording to a corresponding encoding scheme. Each of the data encodingparts 20, 31 and 32 adopts at least one of a PCM (pulse code modulation)scheme and a differential coding scheme. In particular, the first dataencoding part 20 adopts the PCM scheme, the second data encoding part 31adopts a first differential coding scheme using a pilot reference value,and the third data encoding part 32 adopts a second differential codingscheme using a difference from neighbor data, for example.

Hereinafter, for convenience of explanation, the first differentialcoding scheme is named ‘pilot based coding (PBC)’ and the seconddifferential coding scheme is named ‘differential coding (DIFF)’. And,operations of the data encoding parts 20, 31 and 32 shall be explainedin detail with reference to FIGS. 3 to 8 later.

Meanwhile, the entropy encoding part 40 performs variable lengthencoding according to statistical characteristics of data with referenceto an entropy table 41. And, operations of the entropy encoding part 40shall be explained in detail with reference to FIGS. 18 to 22 later.

The bitstream multiplexing part 50 arranges and/or coverts the codeddata to correspond to a transfer specification and then transfers thearranged/converted data in a bitstream form. Yet, if a specific systememploying the present invention does not use the bitstream multiplexingpart 50, it is apparent to those skilled in the art that the system canbe configured without the bitstream multiplexing part 50.

Meanwhile, the decoding apparatus 2 is configured to correspond to theabove-explained encoding apparatus 1.

For instance, referring to FIG. 2, a bitstream demultiplexing part 60receives an inputted bitstream and interprets and classifies variousinformation included in the received bitstream according to a presetformat.

An entropy decoding part 70 recovers the data into the original databefore entropy encoding using an entropy table 71. In this case, it isapparent that the entropy table 71 is identically configured with theformer entropy table 41 of the encoding apparatus 1 shown in FIG. 1.

A first data decoding part 80, a second data decoding part 91 and athird data decoding part 92 perform decoding to correspond to theaforesaid first to third data encoding parts 20, 31 and 32,respectively.

In particular, in case that the second and third data decoding parts 91and 92 perform differential decoding, it is able to integrate overlappeddecoding processes to be handled within one decoding process.

A data reconstructing part 95 recovers or reconstructs data decoded bythe data decoding parts 80, 91 and 92 into original data prior to dataencoding. Occasionally, the decoded data can be recovered into dataresulting from converting or modifying the original data.

By the way, the present invention uses at least two coding schemestogether for the efficient execution of data coding and intends toprovide an efficient coding scheme using correlation between codingschemes.

And, the present invention intends to provide various kinds of datagrouping schemes for the efficient execution of data coding.

Moreover, the present invention intends to provide a data structureincluding the features of the present invention.

In applying the technical idea of the present invention to varioussystems, it is apparent to those skilled in the art that variousadditional configurations should be used as well as the elements shownin FIG. 1 and FIG. 2. For example, data quantization needs to beexecuted or a controller is needed to control the above process.

Data Coding

PCM (pulse code modulation), PBC (pilot based coding) and DIFF(differential coding) applicable as data coding schemes of the presentinvention are explained in detail as follows. Besides, efficientselection and correlation of the data coding schemes shall besubsequently explained as well.

1. PCM (Pulse Code Modulation)

PCM is a coding scheme that converts an analog signal to a digitalsignal. The PCM samples analog signals with a preset interval and thenquantizes a corresponding result. PCM may be disadvantageous in codingefficiency but can be effectively utilized for data unsuitable for PBCor DIFF coding scheme that will be explained later.

In the present invention, the PCM is used together with the PBC or DIFFcoding scheme in performing data coding, which shall be explained withreference to FIGS. 9 to 12 later.

2. PBC (Pilot Based Coding)

2-1. Concept of PBC

PBC is a coding scheme that determines a specific reference within adiscriminated data group and uses the relation between data as a codingtarget and the determined reference.

A value becoming a reference to apply the PBC can be defined as‘reference value’, ‘pilot’, ‘pilot reference value’ or ‘pilot value’.Hereinafter, for convenience of explanation, it is named ‘pilotreference value’.

And, a difference value between the pilot reference value and datawithin a group can be defined as ‘difference’ or ‘pilot difference’.

Moreover, a data group as a unit to apply the PBC indicates a finalgroup having a specific grouping scheme applied by the aforesaid datagrouping part 10. Data grouping can be executed in various ways, whichshall be explained in detail later.

In the present invention, data grouped in the above manner to have aspecific meaning is defined as ‘parameter’ to explain. This is just forconvenience of explanation and can be replaced by a differentterminology.

The PBC process according to the present invention includes at least twosteps as follows.

First of all, a pilot reference value corresponding to a plurality ofparameters is selected. In this case, the pilot reference value isdecided with reference to a parameter becoming a PBC target.

For instance, a pilot reference value is set to a value selected from anaverage value of parameters becoming PBC targets, an approximate valueof the average value of the parameters becoming the targets, anintermediate value corresponding to an intermediate level of parametersbecoming targets and a most frequently used value among parametersbecoming targets. And, a pilot reference value can be set to a presetdefault value as well. Moreover, a pilot value can be decided by aselection within a preset table.

Alternatively, in the present invention, temporary pilot referencevalues are set to pilot reference values selected by at least two of thevarious pilot reference value selecting methods, coding efficiency iscalculated for each case, the temporary pilot reference valuecorresponding to a case having best coding efficiency is then selectedas a final pilot reference value.

The approximate value of the average is Ceil[P] or Floor[P] when theaverage is P. In this case, Ceil[x] is a maximum integer not exceeding‘x’ and Floor[x] is a minimum integer exceeding ‘x’.

Yet, it is also possible to select an arbitrary fixed default valuewithout referring to parameters becoming PBC targets.

For another instance, as mentioned in the foregoing description, afterseveral values selectable as pilots have been randomly and plurallyselected, a value showing the best coding efficiency can be selected asan optimal pilot.

Secondly, a difference value between the selected pilot and a parameterwithin a group is found. For instance, a difference value is calculatedby subtracting a pilot reference value from a parameter value becoming aPBC target. This is explained with reference to FIG. 2 and FIG. 4 asfollows.

FIG. 3 and FIG. 4 are diagrams to explain PBC coding according to thepresent invention.

For instance, it is assumed that a plurality of parameters (e.g., 10parameters) exist within one group to have the following parametervalues, X[n]={11, 12, 9, 12, 10, 8, 12, 9, 10, 9}, respectively.

If a PBC scheme is selected to encode the parameters within the group, apilot reference value should be selected in the first place. In thisexample, it can be seen that the pilot reference value is set to ‘10’ inFIG. 4.

As mentioned in the foregoing description, it is able to select thepilot reference value by the various methods of selecting a pilotreference value.

Difference values by PBC are calculated according to Formula 1.

d[n]=x[n]−P, where n=0, 1, . . . , 9.  [Formula 1]

In this case, ‘P’ indicates a pilot reference value (=10) and x[n] is atarget parameter of data coding.

A result of PBC according to Formula 1 corresponds to d[n]={1, 2, −1, 2,0, −2, 2, −1, 0, −1}. Namely, the result of PBC coding includes theselected pilot reference value and the calculated d[n]. And, thesevalues become targets of entropy coding that will be explained later.Besides, the PBC is more effective in case that deviation of targetparameter values is small overall.

2-2. PBC Objects

A target of PBC coding is not specified into one. It is possible to codedigital data of various signals by PBC. For instance, it is applicableto audio coding that will be explained later. In the present invention,additional control data processed together with audio data is explainedin detail as a target of PBC coding.

The control data is transferred in addition to a downmixed signal ofaudio and is then used to reconstruct the audio. In the followingdescription, the control data is defined as ‘spatial information orspatial parameter’.

The spatial information includes various kinds of spatial parameterssuch as a channel level difference (hereinafter abbreviated CLD), aninter-channel coherence (hereinafter abbreviated ICC), a channelprediction coefficient (hereinafter abbreviated CPC) and the like.

In particular, the CLD is a parameter that indicates an energydifference between two different channels. For instance, the CLD has avalue ranging between −15 and +15. The ICC is a parameter that indicatesa correlation between two different channels. For instance, the ICC hasa value ranging between 0 and 7. And, the CPC is a parameter thatindicates a prediction coefficient used to generate three channels fromtwo channels. For instance, the CPC has a value ranging between −20 and30.

As a target of PBC coding, a gain value used to adjust a gain of signal,e.g., ADG (arbitrary downmix gain) can be included.

And, ATD (arbitrary tree data) applied to an arbitrary channelconversion box of a downmixed audio signal can become a PBC codingtarget. In particular, the ADG is a parameter that is discriminated fromthe CLD, ICC or CPC. Namely, the ADG corresponds to a parameter toadjust a gain of audio to differ from the spatial information such asCLD, ICC CPC and the like extracted from a channel of an audio signal.Yet, for example of use, it is able to process the ADG or ATD in thesame manner of the aforesaid CLD to raise efficiency of audio coding.

As another target of PBC coding, a partial parameter can be taken intoconsideration. In the present invention, ‘partial parameter’ means aportion of parameter.

For instance, assuming that a specific parameter is represented as nbits, the n bits are divided into at least two parts. And, it is able todefine the two parts as first and second partial parameters,respectively. In case of attempting to perform PBC coding, it is able tofind a difference value between a first partial parameter value and apilot reference value. Yet, the second partial parameter excluded in thedifference calculation should be transferred as a separate value.

In more particular, for instance, in case of n bits indicating aparameter value, a least significant bit (LSB) is defined as the secondpartial parameter and a parameter value constructed with the rest (n−1)upper bits can be defined as the first partial parameter. In this case,it is able to perform PBC on the first partial parameter only. This isbecause coding efficiency can be enhanced due to small deviationsbetween the first partial parameter values constructed with the (n−1)upper bits.

The second partial parameter excluded in the difference calculation isseparately transferred, and is then taken into consideration inreconstructing a final parameter by a decoding part. Alternatively, itis also possible to obtain a second partial parameter by a predeterminedscheme instead of transferring the second partial parameter separately.

PBC coding using characteristics of the partial parameters isrestrictively utilized according to a characteristic of a targetparameter.

For instance, as mentioned in the foregoing description, deviationsbetween the first partial parameters should be small. If the deviationis big, it is unnecessary to utilize the partial parameters. It may evendegrade coding efficiency.

According to an experimental result, the CPC parameter of the aforesaidspatial information is suitable for the application of the PBC scheme.Yet, it is not preferable to apply the CPC parameter to coarsequantization scheme. In case that a quantization scheme is coarse, adeviation between first partial parameters increases.

Besides, the data coding using partial parameters is applicable to DIFFscheme as well as PBC scheme.

In case of applying the partial parameter concept to the CPC parameter,a signal processing method and apparatus for reconstruction areexplained as follows.

For instance, a method of processing a signal using partial parametersaccording to the present invention includes the steps of obtaining afirst partial parameter using a reference value corresponding to thefirst partial parameter and a difference value corresponding to thereference value and deciding a parameter using the first partialparameter and a second partial parameter.

In this case, the reference value is either a pilot reference value or adifference reference value. And, the first partial parameter includespartial bits of the parameter and the second partial parameter includesthe rest bits of the parameter. Moreover, the second partial parameterincludes a least significant bit of the parameter.

The signal processing method further includes the step of reconstructingan audio signal using the decided parameter.

The parameter is spatial information including at least one of CLD, ICC,CPC and ADG.

If the parameter is the CPC and if a quantization scale of the parameteris not coarse, it is able to obtain the second partial parameter.

And, a final parameter is decided by twice multiplying the partialparameter and adding the multiplication result to the second partialparameter.

An apparatus for processing a signal using partial parameters accordingto the present invention includes a first parameter obtaining partobtaining a first partial parameter using a reference valuecorresponding to the first partial parameter and a difference valuecorresponding to the reference value and a parameter deciding partdeciding a parameter using the first partial parameter and a secondpartial parameter.

The signal processing apparatus further includes a second parameterobtaining part obtaining the second partial parameter by receiving thesecond partial parameter.

And, the first parameter obtaining part, the parameter deciding part andthe second partial parameter obtaining part are included within theaforesaid data decoding part 91 or 92.

A method of processing a signal using partial parameters according tothe present invention includes the steps of dividing a parameter into afirst partial parameter and a second partial parameter and generating adifference value using a reference value corresponding to the firstpartial parameter and the first partial parameter.

And, the signal processing method further includes the step oftransferring the difference value and the second partial parameter.

An apparatus for processing a signal using partial parameters accordingto the present invention includes a parameter dividing part dividing aparameter into a first partial parameter and a second partial parameterand a difference value generating part generating a difference valueusing a reference value corresponding to the first partial parameter andthe first partial parameter.

And, the signal processing apparatus further includes a parameteroutputting part transferring the difference value and the second partialparameter.

Moreover, the parameter diving part and the difference value generatingpart are included within the aforesaid data encoding part 31 or 32.

2-3. PBC Conditions

In aspect that PBC coding of the present invention selects a separatepilot reference value and then has the selected pilot reference valueincluded in a bitstream, it is probable that transmission efficiency ofthe PBC coding becomes lower than that of a DIFF coding scheme that willbe explained later.

So, the present invention intends to provide an optimal condition toperform PBC coding.

If the number of data experimentally becoming targets of data codingwithin a group is at least three or higher, PBC coding is applicable.This corresponds to a result in considering efficiency of data coding.It means that DIFF or PCM coding is more efficient than PBC coding iftwo data exist within a group only.

Although PBC coding is applicable to at least three or more data, it ispreferable that PBC coding is applied to a case that at least five dataexist within a group. In other words, a case that PBC coding is mostefficiently applicable is a case that there are at least five databecoming targets of data coding and that deviations between the at leastfive data are small. And, a minimum number of data suitable for theexecution of PBC coding will be decided according to a system and codingenvironment.

Data becoming a target of data coding is given for each data band. Thiswill be explained through a grouping process that will be describedlater. So, for example, the present invention proposes that at leastfive data bands are required for the application of PBC coding in MPEGaudio surround coding that will be explained later.

Hereinafter, a signal processing method and apparatus using theconditions for the execution of PBC are explained as follows.

In a signal processing method according to one embodiment of the presentinvention, if the number of data corresponding to a pilot referencevalue is obtained and if the number of data bands meets a presetcondition, the pilot reference value and a pilot difference valuecorresponding to the pilot reference value are obtained. Subsequently,the data are obtained using the pilot reference value and the pilotdifference value. In particular, the number of the data is obtainedusing the number of the data bands in which the data are included.

In a signal processing method according to another embodiment of thepresent invention, one of a plurality of data coding schemes is decidedusing the number of data and the data are decoded according to thedecided data coding scheme. A plurality of the data coding schemesinclude a pilot coding scheme at least. If the number of the data meetsa preset condition, the data coding scheme is decided as the pilotcoding scheme.

And, the data decoding process includes the steps of obtaining a pilotreference value corresponding to a plurality of the data and a pilotdifference value corresponding to the pilot reference value andobtaining the data using the pilot reference value and the pilotdifference value.

Moreover, in the signal processing method, the data are parameters. And,an audio signal is recovered using the parameters. In the signalprocessing method, identification information corresponding to thenumber of the parameters is received and the number of the parameters isgenerated using the received identification information. By consideringthe number of the data, identification information indicating aplurality of the data coding schemes is hierarchically extracted.

In the step of extracting the identification information, a firstidentification information indicating a first data coding scheme isextracted and a second identification information indicating a seconddata coding scheme is then extracted using the first identificationinformation and the number of the data. In this case, the firstidentification information indicates whether it is a DIFF coding scheme.And, the second identification information indicates whether it is apilot coding scheme or a PCM grouping scheme.

In a signal processing method according to another embodiment of thepresent invention, if the number of a plurality of data meets a presetcondition, a pilot difference value is generated using a pilot referencevalue corresponding to a plurality of the data and the data. Thegenerated pilot difference value is then transferred. In the signalprocessing method, the pilot reference value is transferred.

In a signal processing method according to a further embodiment of thepresent invention, data coding schemes are decided according to thenumber of a plurality of data. The data are then encoded according tothe decided data coding schemes. In this case, a plurality of the datacoding schemes include a pilot coding scheme at least. If the number ofthe data meets a preset condition, the data coding scheme is decided asthe pilot coding scheme.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a number obtaining part obtaining a number ofdata corresponding to a pilot reference value, a value obtaining partobtaining the pilot reference value and a pilot difference valuecorresponding to the pilot reference value if the number of the datameets a preset condition, and a data obtaining part obtaining the datausing the pilot reference value and the pilot difference value. In thiscase, the number obtaining part, the value obtaining part and the dataobtaining part are included in the aforesaid data decoding part 91 or92.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a scheme deciding part deciding one of aplurality of data coding schemes according to a number of a plurality ofdata and a decoding part decoding the data according to the decided datacoding scheme. In this case, a plurality of the data coding schemesinclude a pilot coding scheme at least.

An apparatus for processing a signal according to a further embodimentof the present invention includes a value generating part generating apilot difference value using a pilot reference value corresponding to aplurality of data and the data if a number of a plurality of the datameets a preset condition and an output part transferring the generatedpilot difference value. In this case, the value generating part isincluded in the aforesaid data encoding part 31 or 32.

An apparatus for processing a signal according to another furtherembodiment of the present invention includes a scheme deciding partdeciding a data coding scheme according to a number of a plurality ofdata and an encoding part encoding the data according to the decideddata coding scheme. In this case, a plurality of the data coding schemesinclude a pilot coding scheme at least.

2-4. PBC Signal Processing Method

A signal processing method and apparatus using PBC coding featuresaccording to the present invention are explained as follows.

In a signal processing method according to one embodiment of the presentinvention, a pilot reference value corresponding to a plurality of dataand a pilot difference value corresponding to the pilot reference valueare obtained. Subsequently, the data are obtained using the pilotreference value and the pilot difference value. And, the method mayfurther include a step of decoding at least one of the pilot differencevalue and the pilot reference value. In this case, the PBC applied dataare parameters. And, the method may further include the step ofreconstructing an audio signal using the obtained parameters.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a pilot reference value corresponding to aplurality of data and a pilot difference value corresponding to thepilot reference value and a data obtaining part obtaining the data usingthe pilot reference value and the pilot difference value. In this case,the value obtaining part and the data obtaining part are included in theaforesaid data coding part 91 or 92.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a pilot differencevalue using a pilot reference value corresponding to a plurality of dataand the data and outputting the generated pilot difference value.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value generating part generating apilot difference value using a pilot reference value corresponding to aplurality of data and the data and an output part outputting thegenerated pilot difference value.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of obtaining a pilot referencevalue corresponding to a plurality of gains and a pilot difference valuecorresponding to the pilot reference value and obtaining the gain usingthe pilot reference value and the pilot difference value. And, themethod may further include the step of decoding at least one of thepilot difference value and the pilot reference value. Moreover, themethod may further include the step of reconstructing an audio signalusing the obtained gain.

In this case, the pilot reference value may be an average of a pluralityof the gains, an averaged intermediate value of a plurality of thegains, a most frequently used value of a plurality of the gains, a valueset to a default or one value extracted from a table. And, the methodmay further include the step of selecting the gain having highestencoding efficiency as a final pilot reference value after the pilotreference value has been set to each of a plurality of the gains.

An apparatus for processing a signal according to a further embodimentof the present invention includes a value obtaining part obtaining apilot reference value corresponding to a plurality of gains and a pilotdifference value corresponding to the pilot reference value and a gainobtaining part obtaining the gain using the pilot reference value andthe pilot difference value.

A method of processing a signal according to another further embodimentof the present invention includes the steps of generating a pilotdifference value using a pilot reference value corresponding to aplurality of gains and the gains and outputting the generated pilotdifference value.

And, an apparatus for processing a signal according to another furtherembodiment of the present invention includes a value calculating partgenerating a pilot difference value using a pilot reference valuecorresponding to a plurality of gains and the gains and an outputtingpart outputting the generated pilot difference value.

3. DIFF (Differential Coding)

DIFF coding is a coding scheme that uses relations between a pluralityof data existing within a discriminated data group, which may be called‘differential coding’. In this case, a data group, which is a unit inapplying the DIFF, means a final group to which a specific groupingscheme is applied by the aforesaid data grouping part 10. In the presentinvention, data having a specific meaning as grouped in the above manneris defined as ‘parameter’ to be explained. And, this is the same asexplained for the PBC.

In particular, the DIFF coding scheme is a coding scheme that usesdifference values between parameters existing within a same group, andmore particularly, difference values between neighbor parameters.

Types and detailed application examples of the DIFF coding schemes areexplained in detail with reference to FIGS. 5 to 8 as follows.

3-1. DIFF Types

FIG. 5 is a diagram to explain types of DIFF coding according to thepresent invention. DIFF coding is discriminated according to a directionin finding a difference value from a neighbor parameter.

For instance, DIFF coding types can be classified into DIFF in frequencydirection (hereinafter abbreviated ‘DIFF_FREQ’ or ‘DF’) and DIFF in timedirection (hereinafter abbreviated ‘DIFF_TIME’ or ‘DT’).

Referring to FIG. 5, Group-1 indicates DIFF(DF) calculating a differencevalue in a frequency axis, while Group-2 or Group-3 calculates adifference value in a time axis.

As can be seen in FIG. 5, the DIFF(DT), which calculates a differencevalue in a time axis, is re-discriminated according to a direction ofthe time axis to find a difference value.

For instance, the DIFF(DT) applied to the Group-2 corresponds to ascheme that finds a difference value between a parameter value at acurrent time and a parameter value at a previous time (e.g., Group-1).This is called backward time DIFF(DT) (hereinafter abbreviated‘DT-BACKWARD’).

For instance, the DIFF(DT) applied to the Group-3 corresponds to ascheme that finds a difference value between a parameter value at acurrent time and a parameter value at a next time (e.g., Group-4). Thisis called forward time DIFF(DT) (hereinafter abbreviated ‘DT-FORWARD’).

Hence, as shown in FIG. 5, the Group-1 is a DIFF(DF) coding scheme, theGroup-2 is a DIFF(DT-BACKWARD) coding scheme, and the Group-3 is aDIFF(DT-FORWARD) coding scheme. Yet, a coding scheme of the Group-4 isnot decided.

In the present invention, although DIFF in frequency axis is defined asone coding scheme (e.g., DIFF(DF)) only, definitions can be made bydiscriminating it into ‘DIFF(DF-TOP)’ and ‘DIFF(DF-BOTTOM)’ as well.

3-2. Examples of DIFF Applications

FIGS. 6 to 8 are diagrams of examples to which DIFF coding scheme isapplied.

In FIG. 6, the Group-1 and the Group-2 shown in FIG. 5 are taken asexamples for the convenience of explanation. The Group-1 followsDIFF(DF) coding scheme and its parameter value is x[n]={11, 12, 9, 12,10, 8, 12, 9, 10, 9}. The Group-2 follows DIFF(DF-BACKWARD) codingscheme and its parameter value is y[n]={10, 13, 8, 11, 10, 7, 14, 8, 10,8}.

FIG. 7 shows results from calculating difference values of the Group-1.Since the Group-1 is coded by the DIFF(DF) coding scheme, differencevalues are calculated by Formula 2. Formula 2 means that a differencevalue from a previous parameter is found on a frequency axis.

d[0]=x[0]

d[n]=x[n]−x[n−1], where n=1, 2, . . . , 9.  [Formula 2]

In particular, the DIFF(DF) result of the Group-1 by Formula 2 isd[n]={−11, 1, −3, 3, −2, −2, 4, −3, 1, −1}.

FIG. 8 shows results from calculating difference values of the Group-2.Since the Group-2 is coded by the DIFF(DF-BACKWARD) coding scheme,difference values are calculated by Formula 3. Formula 3 means that adifference value from a previous parameter is found on a time axis.

d[n]=y[n]−x[n], where n=1, 2, . . . , 9.  [Formula 3]

In particular, the DIFF(DF-BACKWARD) result of the Group-2 by Formula 3is d[n]={−1, 1, −1, −1, 0, 01, 2, −1, 0, −1}.

4. Selection for Data Coding Scheme

The present invention is characterized in compressing or reconstructingdata by mixing various data coding schemes. So, in coding a specificgroup, it is necessary to select one coding scheme from at least threeor more data coding schemes. And, identification information for theselected coding scheme should be delivered to a decoding part viabitstream.

A method of selecting a data coding scheme and a coding method andapparatus using the same according to the present invention areexplained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining data codingidentification information and data-decoding data according to a datacoding scheme indicated by the data coding identification information.

In this case, the data coding scheme includes a PBC coding scheme atleast. And, the PBC coding scheme decodes the data using a pilotreference value corresponding to a plurality of data and a pilotdifference value. And, the pilot difference value is generated using thedata and the pilot reference value.

The data coding scheme further includes a DIFF coding scheme. The DIFFcoding scheme corresponds to one of DIFF-DF scheme and DIFF-DT scheme.And, the DIFF-DT scheme corresponds to one of forward timeDIFF-DT(FORWARD) scheme and backward time DIFF-DT(BACKWARD).

The signal processing method further includes the steps of obtainingentropy coding identification information and entropy-decoding the datausing an entropy coding scheme indicated by the entropy codingidentification information.

In the data decoding step, the entropy-decoded data is data-decoded bythe data coding scheme.

And, the signal processing method further includes the step of decodingan audio signal using the data as parameters.

An apparatus for processing a signal according to one embodiment of thepresent invention includes

An identification information obtaining part obtaining data codingidentification information and a decoding part data-decoding dataaccording to a data coding scheme indicated by the data codingidentification information.

In this case, the data coding scheme includes a PBC coding scheme atleast. And, the PBC coding scheme decodes the data using a pilotreference value corresponding to a plurality of data and a pilotdifference value. And, the pilot difference value is generated using thedata and the pilot reference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of data-encoding data according toa data coding scheme and generating to transfer data codingidentification information indicating the data coding scheme.

In this case, the data coding scheme includes a PBC coding scheme atleast. The PBC coding scheme encodes the data using a pilot referencevalue corresponding to a plurality of data and a pilot difference value.And, the pilot difference value is generated using the data and thepilot reference value.

An apparatus for processing a signal according to another embodiment ofthe present invention includes an encoding part data-encoding dataaccording to a data coding scheme and an outputting part generating totransfer data coding identification information indicating the datacoding scheme.

In this case, the data coding scheme includes a PBC coding scheme atleast. The PBC coding scheme encodes the data using a pilot referencevalue corresponding to a plurality of data and a pilot difference value.And, the pilot difference value is generated using the data and thepilot reference value.

A method of selecting a data coding scheme and a method of transferringcoding selection identification information by optimal transmissionefficiency according to the present invention are explained as follows.

4-1. Data Coding Identifying Method Considering Frequency of Use

FIG. 9 is a block diagram to explain a relation in selecting one of atleast three coding schemes according to the present invention.

Referring to FIG. 9, it is assumed that there exist first to third dataencoding parts 53, 52 and 51, that frequency of use of the first dataencoding part 53 is lowest, and that frequency of use of the third dataencoding part 51 is highest.

For convenience of explanation, with reference to total ‘100’, it isassumed that frequency of use of the first data encoding part 53 is‘10’, that frequency of use of the second data encoding part 52 is ‘30’,and that frequency of use of the third data encoding part 51 is ‘60’. Inparticular, for 100 data groups, it can be regarded PCM scheme isapplied 10 times, PBC scheme is applied 30 times, and DIFF scheme isapplied 60 times.

On the above assumptions, a number of bits necessary for identificationinformation to identify three kinds of coding schemes is calculated in afollowing manner.

For example, according to FIG. 9, since 1-bit first information is used,100 bits are used as the first information to identify coding schemes oftotal 100 groups. Since the third data encoding part 51 having thehighest frequency of use is identified through the 100 bits, the rest of1-bit second information is able to discriminate the first data encodingpart 53 and the second data encoding part 52 using 40 bits only.

Hence, identification information to select the per-group coding typefor total 100 data groups needs total 140 bits resulting from ‘firstinformation (100 bits)+second information (40 bits)’.

FIG. 10 is a block diagram to explain a relation in selecting one of atleast three coding schemes according to a related art.

Like FIG. 9, for convenience of explanation, with reference to total‘100’, it is assumed that frequency of use of the first data encodingpart 53 is ‘10’, that frequency of use of the second data encoding part52 is ‘30’, and that frequency of use of the third data encoding part 51is ‘60’.

In FIG. 10, a number of bits necessary for identification information toidentify three coding scheme types is calculated in a following manner.

First of all, according to FIG. 10, since 1-bit first information isused, 100 bits are used as the first information to identify codingschemes of total 100 groups.

The first data encoding part 53 having the lowest frequency of use ispreferentially identified through the 100 bits. So, the rest of 1-bitsecond information needs total 90 bits more to discriminate the seconddata encoding part 52 and the third data encoding part 51.

Hence, identification information to select the per-group coding typefor total 100 data groups needs total 190 bits resulting from ‘firstinformation (100 bits)+second information (90 bits)’.

Comparing the case shown in FIG. 9 and the case shown in FIG. 10, it canbe seen that the data coding selection identification information shownin FIG. 9 is more advantageous in transmission efficiency.

Namely, in case that there exist at least three or more data codingschemes, the present invention is characterized in utilizing differentidentification information instead of discriminating two coding schemetypes similar to each other in frequency of use by the sameidentification information.

For instance, in case that the first data encoding part 51 and thesecond data encoding part 52, as shown in FIG. 10, are classified as thesame identification information, data transmission bits increase tolower transmission efficiency.

In case that there exist at least three data coding types, the presentinvention is characterized in discriminating a data coding scheme havinghighest frequency of use by first information. So, by secondinformation, the rest of the two coding schemes having low frequency ofuse each are discriminated.

FIG. 11 and FIG. 12 are flowcharts for the data coding selecting schemeaccording to the present invention, respectively.

In FIG. 11, it is assumed that DIFF coding is a data coding schemehaving highest frequency of use. In FIG. 12, it is assumed that PBCcoding is a data coding scheme having highest frequency of use.

Referring to FIG. 11, a presence or non-presence of PCM coding havinglowest frequency of use is checked (S10). As mentioned in the foregoingdescription, the check is performed by first information foridentification.

As a result of the check, if it is the PCM coding, it is checked whetherit is PBC coding (S20). This is performed by second information foridentification.

In case that frequency of use of DIFF coding is 60 times among total 100times, identification information for a per-group coding type selectionfor the same 100 data groups needs total 140 bits of ‘first information(100 bits)+second information (40 bits)’.

Referring to FIG. 12, like FIG. 11, a presence or non-presence of PCMcoding having lowest frequency of use is checked (S30). As mentioned inthe foregoing description, the check is performed by first informationfor identification.

As a result of the check, if it is the PCM coding, it is checked whetherit is DIFF coding (S40). This is performed by second information foridentification.

In case that frequency of use of DIFF coding is 80 times among total 100times, identification information for a per-group coding type selectionfor the same 100 data groups needs total 120 bits of ‘first information(100 bits)+second information (20 bits)’.

A method of identifying a plurality of data coding schemes and a signalprocessing method and apparatus using the same according to the presentinvention are explained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of extracting identificationinformation indicating a plurality of data coding schemes hierarchicallyand decoding data according to the data coding scheme corresponding tothe identification information.

In this case, the identification information indicating a PBC codingscheme and a DIFF coding scheme included in a plurality of the datacoding schemes is extracted from different layers.

In the decoding step, the data are obtained according to the data codingscheme using a reference value corresponding to a plurality of data anda difference value generated using the data. In this case, the referencevalue is a pilot reference value or a difference reference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of extracting identificationinformation indicating at least three or more data coding schemeshierarchically. In this case, the identification information indicatingtwo coding schemes having high frequency of use of the identificationinformation is extracted from different layers.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of extracting identificationinformation hierarchically according to frequency of use of theidentification information indicating a data coding scheme and decodingdata according to the data decoding scheme corresponding to theidentification information.

In this case, the identification information is extracted in a manner ofextracting first identification information and second identificationinformation hierarchically. The first identification informationindicates whether it is a first data coding scheme and the secondidentification information indicates whether it is a second data codingscheme.

The first identification information indicates whether it is a DIFFcoding scheme. And, the second identification information indicateswhether it is a pilot coding scheme or a PCM grouping scheme.

The first data coding scheme can be a PCM coding scheme. And, the seconddata coding scheme can be a PBC coding scheme or a DIFF coding scheme.

The data are parameters, and the signal processing method furtherincludes the step of reconstructing an audio signal using theparameters.

An apparatus for processing a signal according to one embodiment of thepresent invention includes an identifier extracting part (e.g., ‘710’ inFIG. 13) hierarchically extracting identification informationdiscriminating a plurality of data coding schemes and a decoding partdecoding data according to the data coding scheme corresponding to theidentification information.

A method of processing a signal according to another further embodimentof the present invention includes the steps of encoding data accordingto a data coding scheme and generating identification informationdiscriminating data coding schemes differing from each other infrequency of use used in encoding the data.

In this case, the identification information discriminates a PCM codingscheme and a PBC coding scheme from each other. In particular, theidentification information discriminates a PCM coding scheme and a DIFFcoding scheme.

And, an apparatus for processing a signal according to another furtherembodiment of the present invention includes an encoding part encodingdata according to a data coding scheme and an identification informationgenerating part (e.g., ‘400’ in FIG. 11) generating identificationinformation discriminating data coding schemes differing from each otherin frequency of use used in encoding the data.

4-2. Inter-Data-Coding Relations

First of all, there exist mutually independent and/or dependentrelations between PCM, PBC and DIFF of the present invention. Forinstance, it is able to freely select one of the three coding types foreach group becoming a target of data coding. So, overall data codingbrings a result of using the three coding scheme types in combinationwith each other. Yet, by considering frequency of use of the threecoding scheme types, one of a DIFF coding scheme having optimalfrequency of use and the rest of the two coding schemes (e.g., PCM andPBC) is primarily selected. Subsequently, one of the PCM and the PBC issecondarily selected. Yet, as mentioned in the foregoing description,this is to consider transmission efficiency of identificationinformation but is not attributed to similarity of substantial codingschemes.

In aspect of similarity of coding schemes, the PBC and DIFF are similarto each other in calculating a difference value. So, coding processes ofthe PBC and the DIFF are considerably overlapped with each other. Inparticular, a step of reconstructing an original parameter from adifference value in decoding is defined as ‘delta decoding’ and can bedesigned to be handled in the same step.

In the course of executing PBC or DIFF coding, there may exist aparameter deviating from its range. In this case, it is necessary tocode and transfer the corresponding parameter by separate PCM.

[Grouping]

1. Concept of Grouping

The present invention proposes ‘grouping’ that handles data by bindingprescribed data together for efficiency in coding. In particular, incase of PBC coding, since a pilot reference value is selected by a groupunit, a grouping process needs to be completed as a step prior toexecuting the PBC coding. The grouping is applied to DIFF coding in thesame manner. And, some schemes of the grouping according to the presentinvention are applicable to entropy coding as well, which will beexplained in a corresponding description part later.

Grouping types of the present invention can be classified into ‘externalgrouping’ and ‘internal grouping’ with reference to an executing methodof grouping.

Alternatively, grouping types of the present invention can be classifiedinto ‘domain grouping’, ‘data grouping’ and ‘channel grouping’ withreference to a grouping target.

Alternatively, grouping types of the present invention can be classifiedinto ‘first grouping’, ‘second grouping’ and ‘third grouping’ withreference to a grouping execution sequence.

Alternatively, grouping types of the present invention can be classifiedinto ‘single grouping’ and ‘multiple grouping’ with reference to agrouping execution count.

Yet, the above grouping classifications are made for convenience intransferring the concept of the present invention, which does not putlimitation on its terminologies of use.

The grouping according to the present invention is completed in a mannerthat various grouping schemes are overlapped with each other in use orused in combination with each other.

In the following description, the groping according to the presentinvention is explained by being discriminated into internal grouping andexternal grouping. Subsequently, multiple grouping, in which variousgrouping types coexist, will be explained. And, concepts of domaingrouping and data grouping will be explained.

2. Internal Grouping

Internal grouping means that execution of grouping is internally carriedout. If internal grouping is carried out in general, a previous group isinternally re-grouped to generate a new group or divided groups.

FIG. 13 is a diagram to explaining internal grouping according to thepresent invention.

Referring to FIG. 13, internal grouping according to the presentinvention is carried out by frequency domain unit (hereinafter named‘band’), for example. So, an internal grouping scheme may correspond toa sort of domain grouping occasionally.

If sampling data passes through a specific filter, e.g., QMF (quadraturemirror filter), a plurality of sub-bands are generated. In the sub-bandmode, first frequency grouping is performed to generate first groupbands that can be called parameter bands. The first frequency groping isable to generate parameter bands by binding sub-bands togetherirregularly. So, it is able to configure sizes of the parameter bandsnon-equivalently. Yet, according to a coding purpose, it is able toconfigure the parameter bands equivalently. And, the step of generatingthe sub-bands can be classified as a sort of grouping.

Subsequently, second frequency grouping is performed on the generatedparameter bands to generate second group bands that may be called databands. The second frequency grouping is able to generate data bands byunifying parameter bands with uniform number.

According to a purpose of the coding after completion of the grouping,it is able to execute coding by parameter band unit corresponding to thefirst group band or by data band unit corresponding to the second groupband.

For instance, in applying the aforesaid PBC coding, it is able to selecta pilot reference value (a sort of group reference value) by takinggrouped parameter bands as one group or by taking grouped data bands asone group. The PBC is carried out using the selected pilot referencevalue and detailed operations of the PBC are the same as explained inthe foregoing description.

For another instance, in applying the aforesaid DIFF coding, a groupreference value is decided by taking grouped parameter bands as onegroup and a difference value is then calculated. Alternatively, it isalso possible to decide a group reference value by taking grouped databands as one group and to calculate a difference value. And, detailedoperations of the DIFF are the same as explained in the foregoingdescription.

If the first and/or frequency grouping is applied to actual coding, itis necessary to transfer corresponding information, which will beexplained with reference to FIG. 23 later.

3. External Grouping

External grouping means a case that execution of grouping is externallycarried out. If external grouping is carried out in general, a previousgroup is externally re-grouped to generate a new group or combinedgroups.

FIG. 14 is a diagram to explaining external grouping according to thepresent invention.

Referring to FIG. 14, external grouping according to the presentinvention is carried out by time domain unit (hereinafter named‘timeslot’), for example. So, an external grouping scheme may correspondto a sort of domain grouping occasionally.

First time grouping is performed on a frame including sampling data togenerate first group timeslots. FIG. 14 exemplarily shows that eighttimeslots are generated. The first time grouping has a meaning ofdividing a frame into timeslots in equal size as well.

At least one of the timeslots generated by the first time grouping isselected. FIG. 14 shows a case that timeslots 1, 4, 5, and 8 areselected. According to a coding scheme, it is able to select the entiretimeslots in the selecting step.

The selected timeslots 1, 4, 5, and 8 are then rearranged into timeslots1, 2, 3 and 4. Yet, according to an object of coding, it is able torearrange the selected timeslots 1, 4, 5, and 8 in part. In this case,since the timeslot(s) excluded from the rearrangement is excluded fromfinal group formation, it is excluded from the PBC or DIFF codingtargets.

Second time grouping is performed on the selected timeslots to configurea group handled together on a final time axis.

For instance, timeslots 1 and 2 or timeslots 3 and 4 can configure onegroup, which is called a timeslot pair. For another instance, timeslots1, 2 and 3 can configure one group, which is called a timeslot triple.And, a single timeslot is able to exist not to configure a group withanother timeslot(s).

In case that the first and second time groupings are applied to actualcoding, it is necessary to transfer corresponding information, whichwill be explained with reference to FIG. 23 later.

4. Multiple Grouping

Multiple grouping means a grouping scheme that generates a final groupby mixing the internal grouping, the external grouping and various kindsof other groupings together. As mentioned in the foregoing description,the individual groping schemes according to the present invention can beapplied by being overlapped with each other or in combination with eachother. And, the multiple grouping is utilized as a scheme to raiseefficiency of various coding schemes.

4-1. Mixing Internal Grouping and External Grouping

FIG. 15 is a diagram to explain multiple grouping according to thepresent invention, in which internal grouping and external grouping aremixed.

Referring to FIG. 15, final grouped bands 64 are generated afterinternal grouping has been completed in frequency domain. And, finaltimeslots 61, 62 and 63 are generated after external groping has beencompleted in time domain.

One individual timeslot after completion of grouping is named a dataset. In FIG. 15, reference numbers 61 a, 61 b, 62 a, 62 b and 63indicate data sets, respectively.

In particular two data sets 61 a and 61 b or another two data sets 62 aand 62 b are able to configure a pair by external grouping. The pair ofthe data sets is called ‘data pair’.

After completion of the multiple grouping, PBC or DIFF codingapplication is executed.

For instance, in case of executing the PBC coding, a pilot referencevalue P1, P2 or P3 is selected for the finally completed data pair 61 or62 or each data set 63 not configuring the data pair. The PBC coding isthen executed using the selected pilot reference values.

For instance, in case of executing the DIFF coding, a DIFF coding typeis decided for each of the data sets 61 a, 61 b, 62 a, 62 b and 63. Asmentioned in the foregoing description, a DIFF direction should bedecided for each of the data sets and is decided as one of ‘DIFF-DF’ and‘DIFF-DT’. A process for executing the DIFF coding according to thedecided DIFF coding scheme is the same as mentioned in the foregoingdescription.

In order to configure a data pair by executing external grouping inmultiple grouping, equivalent internal grouping should be performed oneach of the data sets configuring the data pair.

For instance, each of the data sets 61 a and 61 b configuring a datapair has the same data band number. And, each of the data sets 62 a and62 b configuring a data pair has the same data band number. Yet, thereis no problem in that the data sets belonging to different data pairs,e.g., 61 a and 62 a, respectively may differ from each other in the databand number. This means that different internal grouping can be appliedto each data pair.

In case of configuring a data pair, it is able to perform first groupingby internal grouping and second groping by external grouping.

For instance, a data band number after second grouping corresponds to aprescribed multiplication of a data band number after first grouping.This is because each data set configuring a data pair has the same databand number.

4-2. Mixing Internal Grouping and Internal Grouping

FIG. 16 and FIG. 17 are diagrams to explain mixed grouping according toanother embodiments of the present invention, respectively. Inparticular, FIG. 16 and FIG. 17 intensively show mixing of internalgroupings. So, it is apparent that external grouping is performed or canbe performed in FIG. 16 or FIG. 17.

For instance, FIG. 16 shows a case that internal grouping is performedagain on a case that data bands are generated after completion of thesecond frequency grouping. In particular, the data bands generated bythe second frequency grouping are divided into low frequency band andhigh frequency band. In case of specific coding, it is necessary toutilize the low frequency band or the high frequency band separately. Inparticular, a case of separating the low frequency band and the highfrequency band to utilize is called ‘dual mode’.

So, in case of dual mode, data coding is performed by taking the finallygenerated low or high frequency band as one group. For instance, pilotreference values P1 and P2 are generated for low and high frequencybands, respectively and PBC coding is then performed within thecorresponding frequency band.

The dual mode is applicable according to characteristics per channel.So, this is called ‘channel grouping’. And, the dual mode is differentlyapplicable according to a data type as well.

For instance, FIG. 17 shows a case that internal grouping is performedagain on a case that data bands are generated after completion of theaforesaid second frequency grouping. Namely, the data bands generated bythe second frequency grouping are divided into low frequency band andhigh frequency band. In case of specific coding, the low frequency bandis utilized only but the high frequency band needs to be discarded. Inparticular, a case of grouping the low frequency band to utilize only iscalled ‘low frequency channel (LFE) mode’.

In the low frequency channel (LFE) mode’, data coding is performed bytaking the finally generated low frequency band as one group.

For instance, a pilot reference value P1 is generated for a lowfrequency band and PBC coding is then performed within the correspondinglow frequency band. Yet, it is possible to generate new data bands byperforming internal grouping on a selected low frequency band. This isto intensively group the low frequency band to represent.

And, the low frequency channel (LFE) mode is applied according to a lowfrequency channel characteristic and can be called ‘channel grouping’.

5. Domain Grouping and Data Grouping

Grouping can be classified into domain grouping and data grouping withreference to targets of the grouping.

The domain grouping means a scheme of grouping units of domains on aspecific domain (e.g., frequency domain or time domain). And, the domaingrouping can be executed through the aforesaid internal grouping and/orexternal grouping.

And, the data grouping means a scheme of grouping data itself. The datagrouping can be executed through the aforesaid internal grouping and/orexternal grouping.

In a special case of data grouping, groping can be performed to beusable in entropy coding. For instance, the data grouping is used inentropy coding real data in a finally completed grouping state shown inFIG. 15. Namely, data are processed in a manner that two dataneighboring to each other in one of frequency direction and timedirection are bound together.

Yet, in case that the data grouping is carried out in the above manner,data within a final group are re-grouped in part. So, PBC or DIFF codingis not applied to the data-grouped group (e.g., two data) only. Besides,an entropy coding scheme corresponding to the data grouping will beexplained later.

6. Signal Processing Method Using Grouping

6-1. Signal Processing Method Using Internal Grouping at Least

A signal processing method and apparatus using the aforesaid groupingscheme according to the present invention are explained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining a group referencevalue corresponding to a plurality of data included in one group and adifference value corresponding to the group reference value throughfirst grouping and internal grouping for the first grouping andobtaining the data using the group reference value and the differencevalue.

The present invention is characterized in that a number of the datagrouped by the first grouping is greater than a number of the datagrouped by the internal grouping. In this case, the group referencevalue can be a pilot reference value or a difference reference value.

The method according to one embodiment of the present invention furtherincludes the step of decoding at least one of the group reference valueand the difference value. In this case, the pilot reference value isdecided per the group.

And, numbers of the data included in internal groups through theinternal grouping are set in advance, respectively. In this case, thenumbers of the data included in the internal groups are different fromeach other.

The first grouping and the internal grouping are performed on the dataon a frequency domain. In this case, the frequency domain may correspondto one of a hybrid domain, a parameter band domain, a data band domainand a channel domain.

And, the present invention is characterized in that a first group by thefirst grouping includes a plurality of internal groups by the internalgrouping.

The frequency domain of the present invention is discriminated by afrequency band. The frequency band becomes sub-bands by the internalgrouping. The sub-bands become parameter bands by the internal grouping.The parameter bands become data bands by the internal grouping. In thiscase, a number of the parameter bands can be limited to maximum 28. And,the parameter bands are grouped by 2, 5 or 10 into one data band.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a value obtaining part obtaining a groupreference value corresponding to a plurality of data included in onegroup and a difference value corresponding to the group reference valuethrough first grouping and internal grouping for the first grouping anda data obtaining part obtaining the data using the group reference valueand the difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a difference valueusing a group reference value corresponding to a plurality of dataincluded in one group through first grouping and internal grouping forthe first grouping and the data and transferring the generateddifference value.

And, an apparatus for processing a signal according to anotherembodiment of the present invention includes a value generating partgenerating a difference value using a group reference valuecorresponding to a plurality of data included in one group through firstgrouping and internal grouping for the first grouping and the data andan outputting part transferring the generated difference value.

6-2. Signal Processing Method Using Multiple Grouping

A signal processing method and apparatus using the aforesaid groupingscheme according to the present invention are explained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining a group referencevalue corresponding to a plurality of data included in one group throughgrouping and a difference value corresponding to the group referencevalue and obtaining the data using the group reference value and thedifference value.

In this case, the group reference value can be one of a pilot referencevalue and a difference reference value.

And, the grouping may correspond to one of external grouping andexternal grouping.

Moreover, the grouping may correspond to one of domain grouping and datagrouping.

The data grouping is performed on a domain group. And, a time domainincluded in the domain grouping includes at least one of a timeslotdomain, a parameter set domain and a data set domain.

A frequency domain included in the domain grouping may include at leastone of a sample domain, a sub-band domain, a hybrid domain, a parameterband domain, a data band domain and a channel domain.

One difference reference value will be set from a plurality of the dataincluded in the group. And, at least one of a grouping count, a groupingrange and a presence or non-presence of the grouping is decided.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a value obtaining part obtaining a groupreference value corresponding to a plurality of data included in onegroup through grouping and a difference value corresponding to the groupreference value and a data obtaining part obtaining the data using thegroup reference value and the difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a difference valueusing a group reference value corresponding to a plurality of dataincluded in one group through grouping and the data and transferring thegenerated difference value.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value generating part generating adifference value using a group reference value corresponding to aplurality of data included in one group through grouping and the dataand an outputting part transferring the generated difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of obtaining a group referencevalue corresponding to a plurality of data included in one group throughgrouping including first grouping and second grouping and a firstdifference value corresponding to the group reference value andobtaining the data using the group reference value and the firstdifference value.

In this case, the group reference value may include a pilot referencevalue or a difference reference value.

The method further includes the step of decoding at least one of thegroup reference value and the first difference value. And, the firstpilot reference value is decided per the group.

The method further includes the steps of obtaining a second pilotreference value corresponding to a plurality of the first pilotreference values and a second difference value corresponding to thesecond pilot reference value and obtaining the first pilot referencevalue using the second pilot reference value and the second differencevalue.

In this case, the second grouping may include external or internalgrouping for the first grouping.

The grouping is performed on the data on at least one of a time domainand a frequency domain. In particular, the grouping is a domain groupingthat groups at least one of the time domain and the frequency domain.

The time domain may include a timeslot domain, a parameter set domain ora data set domain.

The frequency domain may include a sample domain, a sub-band domain, ahybrid domain, a parameter band domain, a data band domain or a channeldomain. And, the grouped data is an index or parameter.

The first difference value is entropy-decoded using an entropy tableindicated by the index included in one group through the first grouping.And, the data is obtained using the group reference value and theentropy-decoded first difference value.

The first difference value and the group reference value areentropy-decoded using an entropy table indicated by the index includedin one group through the first grouping. And, the data is obtained usingthe entropy-decoded group reference value and the entropy-decoded firstdifference value.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value obtaining part obtaining a groupreference value corresponding to a plurality of data included in onegroup through grouping including first grouping and second grouping anda difference value corresponding to the group reference value and a dataobtaining part obtaining the data using the group reference value andthe difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a difference valueusing a group reference value corresponding to a plurality of dataincluded in one group through grouping including first grouping andsecond grouping and the data and transferring the generated differencevalue.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value generating part generating adifference value using a group reference value corresponding to aplurality of data included in one group through grouping including firstgrouping and second grouping and the data and an outputting parttransferring the generated difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of obtaining a group referencevalue corresponding to a plurality of data included in one group throughfirst grouping and external grouping for the first grouping and adifference value corresponding to the group reference value andobtaining the data using the group reference value and the differencevalue.

In this case, a first data number corresponding to a number of the datagrouped by the first grouping is smaller than a second data numbercorresponding to a number of the data grouped by the external grouping.And, a multiplication relation exists between the first data number andthe second data number.

The group reference value may include a pilot reference value or adifference reference value.

The method further includes the step of decoding at least one of thegroup reference value and the difference value.

The pilot reference value is decoded per the group.

The grouping is performed on the data on at least one of a time domainand a frequency domain. The time domain may include a timeslot domain, aparameter set domain or a data set domain. And, the frequency domain mayinclude a sample domain, a sub-band domain, a hybrid domain, a parameterband domain, a data band domain or a channel domain.

The method further includes the step of reconstructing the audio signalusing the obtained data as parameters. And, the external grouping mayinclude paired parameters.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value obtaining part obtaining a groupreference value corresponding to a plurality of data included in onegroup through first grouping and external grouping for the firstgrouping and a difference value corresponding to the group referencevalue and a data obtaining part obtaining the data using the groupreference value and the difference value.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of generating a difference valueusing a group reference value corresponding to a plurality of dataincluded in one group through first grouping and external grouping forthe first grouping and the data and transferring the generateddifference value.

And, an apparatus for processing a signal according to a furtherembodiment of the present invention includes a value generating partgenerating a difference value using a group reference valuecorresponding to a plurality of data included in one group through firstgrouping and external grouping for the first grouping and the data andan outputting part transferring the generated difference value.

6.3. Signal Processing Method Using Data Grouping at Least

A signal processing method and apparatus using the aforesaid groupingscheme according to the present invention are explained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining a group referencevalue corresponding to a plurality of data included in one group throughdata grouping and internal grouping for the data grouping and adifference value corresponding to the group reference value andobtaining the data using the group reference value and the differencevalue.

In this case, a number of the data included in the internal grouping issmaller than a number of the data included in the data grouping. And,the data correspond to parameters.

The internal grouping is performed on a plurality of the data-groupeddata entirely. In this case, the internal grouping can be performed pera parameter band.

The internal grouping can be performed on a plurality of thedata-grouped data partially. In this case, the internal grouping can beperformed per a channel of each of a plurality of the data-grouped data.

The group reference value can include a pilot reference value or adifference reference value.

The method may further include the step of decoding at least one of thegroup reference value and the difference value. In this case, the pilotreference value is decided per the group.

The data grouping and the internal grouping are performed on the data ona frequency domain.

The frequency domain may include one of a sample domain, a sub-banddomain, a hybrid domain, a parameter band domain, a data band domain anda channel domain. In obtaining the data, grouping information for atleast one of the data grouping and the internal grouping is used.

The grouping information includes at least one of a position of eachgroup, a number of each group, a presence or non-presence of applyingthe group reference value per a group, a number of the group referencevalues, a codec scheme of the group reference value and a presence ornon-presence of obtaining the group reference value.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a value obtaining part obtaining a groupreference value corresponding to a plurality of data included in onegroup through data grouping and internal grouping for the data groupingand a difference value corresponding to the group reference value and adata obtaining part obtaining the data using the group reference valueand the difference value.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a difference valueusing a group reference value corresponding to a plurality of dataincluded in one group through data grouping and internal grouping forthe data grouping and the data and transferring the generated differencevalue.

And, an apparatus for processing a signal according to anotherembodiment of the present invention includes a value generating partgenerating a difference value using a group reference valuecorresponding to a plurality of data included in one group through datagrouping and internal grouping for the data grouping and the data and anoutputting part transferring the generated difference value.

Entropy Coding

1. Concept of Entropy Coding

Entropy coding according to the present invention means a process forperforming variable length coding on a result of the data coding.

In general, entropy coding processes occurrence probability of specificdata in a statistical way. For instance, transmission efficiency israised overall in a manner of allocating less bits to data having highfrequency of occurrence in probability and more bits to data having lowfrequency of occurrence in probability.

And, the present invention intends to propose an efficient entropycoding method, which is different from the general entropy coding,interconnected with the PBC coding and the DIFF coding.

1-1. Entropy Table

First of all, a predetermined entropy table is necessary for entropycoding. The entropy table is defined as a codebook. And, an encodingpart and a decoding part use the same table.

The present invention proposes an entropy coding method and a uniqueentropy table to process various kinds of data coding resultsefficiently.

1-2. Entropy Coding Types (1D/2D)

Entropy coding of the present invention is classified into two types.One is to derive one index (index 1) through one entropy table, and theother is to derive two consecutive indexes (index 1 and index 2) throughone entropy table. The former is named ‘1D (one-dimensional) entropycoding’ and the latter is named ‘2D (two-dimensional) entropy coding’.

FIG. 18 is an exemplary diagram of 1D and 2D entropy table according tothe present invention. Referring to FIG. 18, an entropy table of thepresent invention basically includes an index field, a length field anda codeword field.

For instance, if specific data (e.g., pilot reference value, differencevalue, etc.) is calculated through the aforesaid data coding, thecorresponding data (corresponding to ‘index’) has a codeword designatedthrough the entropy table. The codeword turns into a bitstream and isthen transferred to a decoding part.

An entropy decoding part having received the codeword decides theentropy table having used for the corresponding data and then derives anindex value using the corresponding codeword and a bit lengthconfiguring the codeword within the decided table. In this case, thepresent invention represents a codeword as hexadecimal.

A positive sign (+) or a negative sign (−) of an index value derived by1D or 2D entropy coding is omitted. So, it is necessary to assign thesign after completion of the 1D or 2D entropy coding.

In the present invention, the sign is assigned differently according to1D or 2D.

For instance, in case of 1D entropy coding, if a corresponding index isnot ‘0’, a separate 1-bit sign bit (e.g., ‘bsSign’) is allocated andtransferred.

In case of 2D entropy coding, since two indexes are consecutivelyextracted, whether to allocate a sign bit is decided in a manner ofprogramming a relation between the two extracted indexes. In this case,the program uses an added value of the two extracted indexes, adifference value between the two extracted indexes and a maximumabsolute value (lav) within a corresponding entropy table. This is ableto reduce a number of transmission bits, compared to a case that a signbit is allocated to each index in case of a simple 2D.

The 1D entropy table, in which indexes are derived one by one, is usablefor all data coding results. Yet, the 2D entropy table, in which twoindexes are derived each, has a restricted use for a specific case.

For instance, if data coding is not a pair through the aforesaidgrouping process, the 2D entropy table has a restricted use in part.And, a use of the 2D entropy table is restricted on a pilot referencevalue calculated as a result of PBC coding.

Therefore, as mentioned in the foregoing description, entropy coding ofthe present invention is characterized in utilizing a most efficiententropy coding scheme in a manner that entropy coding is interconnectedwith the result of data coding. This is explained in detail as follows.

1-3. 2D Method (Time Pairing/Frequency Paring)

FIG. 19 is an exemplary diagram of two methods for 2D entropy codingaccording to the present invention. 2D entropy coding is a process forderiving two indexes neighboring to each other. So, the 2D entropycoding can be discriminated according to a direction of the twoconsecutive indexes.

For instance, a case that two indexes are neighbor to each other infrequency direction is called ‘2D-Freqeuncy Pairing (hereinafterabbreviated 2D-FP)’. And, a case that two indexes are neighbor to eachother in time direction is called ‘2D-Time Pairing (hereinafterabbreviated 2D-TP)’.

Referring to FIG. 19, the 2D-FP and the 2D-TP are able to configureseparate index tables, respectively. An encoder has to decide a mostefficient entropy coding scheme according to a result of data decoding.

A method of deciding entropy coding interconnected with data codingefficiently is explained in the following description.

1-4. Entropy Coding Signal Processing Method

A method of processing a signal using entropy coding according to thepresent invention is explained as follows.

In a method of processing a signal according to one embodiment of thepresent invention, a reference value corresponding to a plurality ofdata and a difference value corresponding to the reference value areobtained. Subsequently, the difference value is entropy-decoded. Thedata is then obtained using the reference value and the entropy-decodeddifference value.

The method further includes the step of entropy-decoding the referencevalue. And, the method may further include the step of obtaining thedata using the entropy-decoded reference value and the entropy-decodeddifference value.

The method can further include the step of obtaining entropy codingidentification information. And, the entropy coding is performedaccording to an entropy coding scheme indicated by the entropy codingidentification information.

In this case, the entropy coding scheme is one of a 1D coding scheme anda multi-dimensional coding scheme (e.g., 2D coding scheme). And, themulti-dimensional coding scheme is one of a frequency pair (FP) codingscheme and a time pair (TP) coding scheme.

The reference value may include one of a pilot reference value and adifference reference value.

And, the signal processing method can further include the step ofreconstructing the audio signal using the data as parameters.

An apparatus for processing a signal according to one embodiment of thepresent invention includes a value obtaining part obtaining a referencevalue corresponding to a plurality of data and a difference valuecorresponding to the reference value, an entropy decoding partentropy-decoding the difference value, and a data obtaining partobtaining the data using the reference value and the entropy-decodeddifference value.

In this case, the value obtaining part is included in the aforesaidbitstream demultiplexing part 60 and the data obtaining part is includedwithin the aforesaid data decoding part 91 or 92.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating a difference valueusing a reference value corresponding to a plurality of data and thedata, entropy-encoding the generated difference value, and outputtingthe entropy-encoded difference value.

In this case, the reference value is entropy-encoded. Theentropy-encoded reference value is transferred.

The method further includes the step of generating an entropy codingscheme used for the entropy encoding. And, the generated entropy codingscheme is transferred.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value generating part generating adifference value using a reference value corresponding to a plurality ofdata and the data, an entropy encoding part entropy-encoding thegenerated difference value, and an outputting part outputting theentropy-encoded difference value.

In this case, the value generating part is included within the aforesaiddata encoding part 31 or 32. And, the outputting part is included withinthe aforesaid bitstream multiplexing part 50.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of obtaining data corresponding toa plurality of data coding schemes, deciding an entropy table for atleast one of a pilot reference value and a pilot difference valueincluded in the data using an entropy table identifier unique to thedata coding scheme, and entropy-decoding at least one of the pilotreference value and the pilot difference value using the entropy table.

In this case, the entropy table identifier is unique to one of a pilotcoding scheme, a frequency differential coding scheme and a timedifferential coding scheme.

And, the entropy table identifier is unique to each of the pilotreference value and the pilot difference value.

The entropy table is unique to the entropy table identifier and includesone of a pilot table, a frequency differential table and a timedifferential table.

Alternatively, the entropy table is not unique to the entropy tableidentifier and one of a frequency differential table and a timedifferential table can be shared.

The entropy table corresponding to the pilot reference value is able touse a frequency differential table. In this case, the pilot referencevalue is entropy-decoded by the 1D entropy coding scheme.

The entropy coding scheme includes a 1D entropy coding scheme and a 2Dentropy coding scheme. In particular, the 2D entropy coding schemeincludes a frequency pair (2D-FP) coding scheme and a time pair (2D-TP)coding scheme.

And, the present method is able to reconstruct the audio signal usingthe data as parameters.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a value obtaining part obtaining a pilotreference value corresponding to a plurality of data and a pilotdifference value corresponding to the pilot reference value and anentropy decoding part entropy-decoding the pilot difference value. And,the apparatus includes a data obtaining part obtaining the data usingthe pilot reference value and the entropy-decoded pilot differencevalue.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of generating a plot differencevalue using a pilot reference value corresponding to a plurality of dataand the data, entropy-encoding the generated pilot difference value, andtransferring the entropy-encoded pilot difference value.

In this case, a table used for the entropy encoding may include a pilotdedicated table.

The method further includes the step of entropy-encoding the pilotreference value. And, the entropy-encoded pilot reference value istransferred.

The method further includes the step of generating an entropy codingscheme used for the entropy encoding. And, the generated entropy codingscheme is transferred.

An apparatus for processing a signal according to a further embodimentof the present invention includes a value generating part generating aplot difference value using a pilot reference value corresponding to aplurality of data and the data, an entropy encoding partentropy-encoding the generated pilot difference value, and an outputtingpart transferring the entropy-encoded pilot difference value.

2. Relation to Data Coding

As mentioned in the foregoing description, the present invention hasproposed three kinds of data coding schemes. Yet, entropy coding is notperformed on the data according to the PCM scheme. Relations between PBCcoding and entropy coding and relations between DIF coding and entropycoding are separately explained in the following description.

2-1. PBC Coding and Entropy Coding

FIG. 20 is a diagram of an entropy coding scheme for PBC coding resultaccording to the present invention.

As mentioned in the foregoing description, after completion of PBCcoding, one pilot reference value and a plurality of differences valuesare calculated. And, all of the pilot reference value and the differencevalues become targets of entropy coding.

For instance, according to the aforesaid grouping method, a group towhich PBC coding will be applied is decided. In FIG. 20, for convenienceof explanation, a case of a pair on a time axis and a case of non-pairon a time axis are taken as examples. Entropy coding after completion ofPBC coding is explained as follows.

First of all, a case 83 that PBC coding is performed on non-pairs isexplained. 1D entropy coding is performed on one pilot reference valuebecoming an entropy coding target, and 1D entropy coding or 2D-FPentropy coding can be performed on the rest difference values.

In particular, since one group exists for one data set on a time axis incase of non-pair, it is unable to perform 2D-TP entropy coding. Even if2D-FP is executed, 1D entropy coding should be performed on a parametervalue within a last band 81 a failing to configure a pair after pairs ofindexes have been derived. Once a per-data entropy coding scheme isdecided, a codeword is generated using a corresponding entropy table.

Since the present invention relates to a case that one pilot referencevalue is generated for one group for example, 1D entropy coding shouldbe performed. Yet, in another embodiment of the present invention, if atleast two pilot reference values are generated from one group, it may bepossible to perform 2D entropy coding on consecutive pilot referencevalues.

Secondly, a case 84 of performing PBC coding on pairs is explained asfollows.

1D entropy coding is performed on one pilot reference value becoming anentropy coding target, and 1D entropy coding, 2D-FP entropy coding or2D-TP entropy coding can be performed on the rest difference values.

In particular, since one group exists for two data sets neighbor to eachother on a time axis in case of pairs, it is able to perform 2D-TPentropy coding. Even if 2D-FP is executed, 1D entropy coding should beperformed on a parameter value within a last band 81 b or 81 c failingto configure a pair after pairs of indexes have been derived. Yet, ascan be confirmed in FIG. 20, in case of applying 2D-TP entropy coding, alast band failing to configure a pair does not exist.

2-2. DIFF Coding and Entropy Coding

FIG. 21 is a diagram of entropy coding scheme for DIFF coding resultaccording to the present invention.

As mentioned in the foregoing description, after completion of DIFFcoding, one pilot reference value and a plurality of differences valuesare calculated. And, all of the pilot reference value and the differencevalues become targets of entropy coding. Yet, in case of DIFF-DT, areference value may not exist.

For instance, according to the aforesaid grouping method, a group towhich DIFF coding will be applied is decided. In FIG. 21, forconvenience of explanation, a case of a pair on a time axis and a caseof non-pair on a time axis are taken as examples. And, FIG. 21 shows acase that a data set as a unit of data coding is discriminated intoDIFF-DT in time axis direction and DIFF-DF in frequency axis directionaccording to DIFF coding direction.

Entropy coding after completion of DIFF coding is explained as follows.

First of all, a case that DIFF coding is performed on non-pairs isexplained. In case of non-pairs, one data set exists on a time axis.And, the data set may become DIFF-DF or DIFF-DT according to DIF codingdirection.

For instance, if one data set of non-pair is DIFF-DF (85), a referencevalue becomes a parameter value within a first band 82 a. 1D entropycoding is performed on the reference value and 1D entropy coding or2D-FP entropy coding can be performed on the rest difference values.

Namely, in case of DIFF-DF as well as non-pair, one group for one dataset exists on a time axis. So, it is unable to perform 2D-TP entropycoding. Even if 2D-FP is executed, after pairs of indexes have beenderived, 1D entropy coding should be performed on a parameter valuewithin a last parameter band 83 a failing to configure a pair. Once acoding scheme is decoded for each data, a codeword is generated using acorresponding entropy table.

For instance, in case that one data set of non-pair is DIFF-DT (86),since a reference value does not exist within the corresponding dataset, ‘first band’ processing is not performed. So, 1D entropy coding or2D-FP entropy coding can be performed on the difference values.

In case of DIFF-DT as well as non-pair, a data set to find a differencevalue may be a neighbor data set failing to configure a data pair or adata set within another audio frame.

Namely, in case of DIFF-DT as well as non-pair (86), there exists onegroup for one data set on a time axis. So, it is unable to perform 2D-TPentropy coding. Even if 2D-FP is executed, after pairs of indexes havebeen derived, 1D entropy coding should be performed on a parameter valuewithin a last parameter band failing to configure a pair. Yet, FIG. 21just shows a case that a last band failing to configure a pair does notexist, for example.

Once a coding scheme is decoded for each data, a codeword is generatedusing a corresponding entropy table.

Secondly, a case that DIFF coding is performed on pairs is explained. Incase that data coding is performed on pairs, two data sets configure onegroup on a time axis. And, each of the data sets within the group canbecome DIFF-DF or DIFF-DT according to DIFF coding direction. So, it canbe classified into a case that both two data sets configuring a pair areDIFF-DF (87), a case that both two data sets configuring a pair areDIFF-DT, and a case that two data sets configuring a pair have differentcoding directions (e.g., DIFF-DF/DT or DIFF-DT/DF), respectively (88).

For instance, in case that both two data sets configuring a pair areDIFF-DF (i.e., DIFF-DF/DF) (87), if each of the data sets is non-pairedand DIFF-DF, if all available entropy coding schemes are executable.

For instance, each reference value within the corresponding data setbecomes a parameter value within a first band 82 b or 82 c and 1Dentropy coding is performed on the reference value. And, 1D entropycoding or 2D-FP entropy coding can be performed on the rest differencevalues.

Even if 2D-FP is performed within a corresponding data set, after pairsof indexes have been derived, 1D entropy coding should be performed on aparameter value within a last band 83 b or 83 c failing to configure apair. Since two data sets configure a pair, 2D-TP entropy coding can beperformed. In this case, 2D-TP entropy coding is sequentially performedon bands ranging from a next band excluding the first band 82 b or 82 cwithin the corresponding data set to a last band.

If the 2D-TP entropy coding is performed, a last band failing toconfigure a pair is not generated.

Once the entropy coding scheme per data is decided, a codeword isgenerated using a corresponding entropy table.

For instance, in case that both of the two data sets configuring thepair are DIFF-DT (i.e., DIFF-DT/DT) (89), since a reference value doesnot exist within a corresponding data set, first band processing is notperformed. And, 1D entropy coding or 2D-Fp entropy coding can beperformed on all the difference values within each of the data sets.

Even if 2D-FP is performed within a corresponding data set, after pairsof indexes have been derived, 1D entropy coding should be performed on aparameter value within a last band failing to configure a pair. Yet,FIG. 21 shows an example that a last band failing to configure a pairdoes not exist.

Since two data sets configure a pair, 2D-TP entropy coding isexecutable. In this case, 2D-TP entropy coding is sequentially performedon bands ranging from a first band to a last band within thecorresponding data set.

If the 2D-TP entropy coding is performed, a last band failing toconfigure a pair is not generated.

Once the entropy coding scheme per data is decided, a codeword isgenerated using a corresponding entropy table.

For instance, there may exist a case that two data sets configuring apair have different coding directions, respectively (i.e., DIFF-DF/DT orDIFF-DT/DF) (88). FIG. 21 shows an example of DIFF-DF/DT. In this case,all entropy coding schemes applicable according to corresponding codingtypes can be basically performed on each o the data sets.

For instance, in a data set of DIFF-DF among two data sets configuring apair, 1D entropy coding is performed on a parameter value within a firstband 82 d with a reference value within the corresponding data set(DIFF-DF). And, 1D entropy coding or 2D-FP entropy coding can beperformed on the rest difference values.

Even if 2D-FP is performed within a corresponding data set (DIFF-DF),after pairs of indexes have been derived, 1D entropy coding should beperformed on a parameter value within a last band 83 d failing toconfigure a pair.

For instance, in a data set of DIFF-DT among two data sets configuring apair, since a reference value does not exist, first band processing isnot performed. And, 1D entropy coding or 2D-FP entropy coding can beperformed on all difference values within the corresponding data set(DIFF-DT).

Even if 2D-FP is performed within a corresponding data set (DIFF-DT),after pairs of indexes have been derived, 1D entropy coding should beperformed on a parameter value within a last band failing to configure apair. Yet, FIG. 21 shows an example that a last band failing toconfigure a pair does not exist.

Since the two data sets configuring the pair have the coding directionsdifferent from each other, respectively, 2D-TP entropy coding isexecutable. In this case, 2D-TP entropy coding is sequentially performedon bands ranging from a next band excluding a first band including thefirst band 82 d to a last band.

If the 2D-TP entropy coding is performed, a last band failing toconfigure a pair is not generated.

Once the entropy coding scheme per data is decided, a codeword isgenerated using a corresponding entropy table.

2-3. Entropy Coding and Grouping

As mentioned in the foregoing description, in case of 2D-FP or 2D-TPentropy coding, two indexes are extracted using one codeword. So, thismeans that a grouping scheme is performed for entropy coding. And, thiscan be named ‘time grouping’ or ‘frequency grouping’.

For instance, an encoding part groups two indexes extracted in a datacoding step in frequency or time direction.

Subsequently, the encoding part selects one codeword representing thetwo grouped indexes using an entropy table and then transfers theselected codeword by having it included in a bitstream.

A decoding part receives one codeword resulting from grouping the twoindexes included in the bitstream and the extracts two index valuesusing the applied entropy table.

2-4. Signal Processing Method by Relation between Data Coding andEntropy Coding

The features of the signal processing method according to the presentinvention by the relation between PBC coding and entropy coding and therelation between DIFF coding and entropy coding are explained asfollows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining differenceinformation, entropy-decoding the difference information according to anentropy coding scheme including time grouping and frequency grouping,and data-decoding the difference information according to a datadecoding scheme including a pilot difference, a time difference and afrequency difference. And, detailed relations between data coding andentropy coding are the same as explained in the foregoing description.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of obtaining a digital signal,entropy-decoding the digital signal according to an entropy codingscheme, and data-decoding the entropy-decoded digital signal accordingto one of a plurality of data coding schemes including a pilot codingscheme at least. In this case, the entropy coding scheme can be decidedaccording to the data coding scheme.

An apparatus for processing a signal according to another embodiment ofthe present invention includes a signal obtaining part obtaining adigital signal, an entropy decoding part entropy-decoding the digitalsignal according to an entropy coding scheme, and a data decoding partdata-decoding the entropy-decoded digital signal according to one of aplurality of data coding schemes including a pilot coding scheme atleast.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of data-encoding a digital signalby a data coding scheme, entropy-encoding the data-encoded digitalsignal by an entropy coding scheme, and transferring the entropy-encodeddigital signal. In this case, the entropy coding scheme can be decidedaccording to the data coding scheme.

And, an apparatus for processing a signal according to a furtherembodiment of the present invention includes a data encoding partdata-encoding a digital signal by a data coding scheme and an entropyencoding part entropy-encoding the data-encoded digital signal by anentropy coding scheme. And, the apparatus may further include anoutputting part transferring the entropy-encoded digital signal.

3. Selection for Entropy Table

An entropy table for entropy coding is automatically decided accordingto a data coding scheme and a type of data becoming an entropy codingtarget.

For instance, if a data type is a CLD parameter and if an entropy codingtarget is a pilot reference value, 1D entropy table to which a tablename ‘hcodPilot_CLD’ is given is used for entropy coding.

For instance, if a data type is a CPC parameter, if data coding isDIFF-DF, and if an entropy coding target is a first band value, 1Dentropy table to which a table name ‘hcodFirstband_CPC’ is given is usedfor entropy coding.

For instance, if a data type is an ICC parameter, if a data codingscheme is PBC, and if entropy coding is performed by 2D-TP, 2D-PC/TPentropy table to which a table name ‘hcod2D_ICC_PC_TP_LL’ is given isused for entropy coding. In this case, ‘LL’ within the 2D table nameindicates a largest absolute value (hereinafter abbreviated ‘LAV’)within the table. And, the largest absolute value (LAV) will beexplained later.

For instance, if a data type is an ICC parameter, if a data codingscheme is DIF-DF, and if entropy coding is performed by 2D-FP, 2D-FPentropy table to which a table name ‘hcod2D_ICC_DF_FP_LL’ is given isused for entropy coding.

Namely, it is very important to decide to perform entropy coding usingwhich one of a plurality of entropy tables. And, it is preferable thatan entropy table suitable for a characteristic of each data becomingeach entropy target is configured independent.

Yet, entropy tables for data having attributes similar to each other canbe shared to use. For representative example, if a data type is ‘ADG’ or‘ATD’, it is able to apply the CLD entropy table. And, a ‘first band’entropy table can be applied to a pilot reference value of PBC coding.

A method of selecting an entropy table using the largest absolute value(LAV) is explained in detail as follows.

3-1. Largest Absolute Vale (LAV) of Entropy Table

FIG. 22 is a diagram to explain a method of selecting an entropy tableaccording to the present invention.

A plurality of entropy tables are shown in (a) of FIG. 22, and a tableto select the entropy tables is shown in (b) of FIG. 22.

As mentioned in the foregoing description, there exist a plurality ofentropy tables according to data coding and data types.

For instance, the entropy tables may include entropy tables (e.g.,tables 1 to 4) applicable in case that a data type is ‘xxx’, entropytables (e.g., tables 5 to 8) applicable in case that a data type is‘yyy’, PBC dedicated entropy tables (e.g., tables k to k+1), escapeentropy tables (e.g., tables n−2˜n−1), and an LAV index entropy table(e.g., table n).

In particular, although it is preferable that a table is configured bygiving a codeword to each index that can occur in corresponding data, ifso, a size of the table considerably increases. And, it is inconvenientto manage indexes that are unnecessary or barely occur. In case of a 2Dentropy table, those problems bring more inconvenience due to too manyoccurrences. To solve those problems, the largest absolute value (LAV)is used.

For instance, if a range of an index value for a specific data type(e.g., CLD) is between ‘−X˜+X’ (X=15), at least one LAV having highfrequency of occurrence in probability is selected within the range andis configured into a separate table.

For instance, in configuring a CLD entropy table, it is able to providea table of ‘LAV=3’, a table of ‘LAV=5’, a table of ‘LAV=7’ or a table of‘LAV=9’.

For instance, in (a) of FIG. 22, it is able to set the table-1 91 a tothe CLD table of ‘LAV=3’, the table-2 91 b to the CLD table of ‘LAV=5’,the table-3 91 c to the CLD table of ‘LAV=7’, and the table-4 91 d tothe CLD table of ‘LAV=9’.

Indexes deviating from the LAV range within the LAV table are handled byescape entropy tables (e.g., tables n−2˜n−1).

For instance, in performing coding using the CLD table 91 c of ‘LAV=7’,if an index deviating from a maximum value ‘7’ occurs (e.g., 8, 9, . . ., 15), the corresponding index is separately handled by the escapeentropy table (e.g., tables n−2˜n−1).

Likewise, it is able to set the LAV table for another data type (e.g.,ICC, CPC, etc.) in the same manner of the CLD table. Yet, LAV for eachdata has a different value because a range per data type varies.

For instance, in configuring an ICC entropy table, for example, it isable to provide a table of ‘LAV=1’, a table of ‘LAV=3’, a table of‘LAV=5’, and a table of ‘LAV=7’. In configuring a CPC entropy table, forexample, it is able to provide a table of ‘LAV=3’, a table of ‘LAV=6’, atable of ‘LAV=9’, and a table of ‘LAV=12’.

3-2. Entropy Table for LAV Index

The present invention employs an LAV index to select an entropy tableusing LAV. Namely, LAV value per data type, as shown in (b) of FIG. 22,is discriminated by LAV index.

In particular, to select an entropy table to be finally used, LAV indexper a corresponding data type is confirmed and LAV corresponding to theLAV index is then confirmed. The finally confirmed LAV value correspondsto ‘LL’ in the configuration of the aforesaid entropy table name.

For instance, if a data type is a CLD parameter, if a data coding schemeis DIFF-DF, if entropy coding is performed by 2D-FP, and if ‘LAV=3’, anentropy table to which a table name ‘hcod2D_CLD_DF_FP_(—)03’ is used forentropy coding.

In confirming the per data type LAV index, the present invention ischaracterized in using an entropy table for LAV index separately. Thismeans that LAV index itself is handled as a target of entropy coding.

For instance, the table-n in (a) of FIG. 22 is used as an LAV indexentropy table 91 e. This is represented as Table 1.

TABLE 1 LavIdx Bit length Codeword [hexadecimal/binary] 0 1 0x0 (0 b) 12 0x2 (10 b) 2 3 0x6 (110 b) 3 3 0x7 (111 b)

This table means that LAV index value itself statistically differs infrequency of use.

For instance, since ‘LAV Index=0’ has highest frequency of use, one bitis allocated to it. And, two bits are allocated to ‘LAV Index=1’ havingsecond highest frequency of use. Finally, three bits are allocated to‘LAV=2 or 3’ having low frequency of use.

In case that the LAV Index entropy table 91 e is not used, 2-bitidentification information should be transferred to discriminate fourkinds of LAV Indexes each time an LAV entropy table is used.

Yet, if the LAV Index entropy table 91 e of the present invention isused, it is enough to transfer 1-bit codeword for a case of ‘LAVIndex=0’ having at least 60% frequency of use for example. So, thepresent invention is able to raise transmission efficiency higher thanthat of the related art method.

In this case, the LAV Index entropy table 91 e in Table 1 is applied toa case of four kinds of LAV Indexes. And, it is apparent thattransmission efficiency can be more enhanced if there are more LAVIndexes.

3-3. Signal Processing Method Using Entropy Table Selection

A signal processing method and apparatus using the aforesaid entropytable selection are explained as follows.

A method of processing a signal according to one embodiment of thepresent invention includes the steps of obtaining index information,entropy-decoding the index information, and identifying a contentcorresponding to the entropy-decoded index information.

In this case, the index information is information for indexes havingcharacteristics of frequency of use with probability.

As mentioned in the foregoing description, the index information isentropy-decoded using the index dedicated entropy table 91 e.

The content is classified according to a data type and is used for datadecoding. And, the content may become grouping information.

The grouping information is information for grouping of a plurality ofdata.

And, an index of the entropy table is a largest absolute value (LAV)among indexes included in the entropy table.

Moreover, the entropy table is used in performing 2D entropy decoding onparameters.

An apparatus for processing a signal according to one embodiment of thepresent invention includes an information obtaining part obtaining indexinformation, a decoding part entropy-decoding the index information, andan identifying part identifying a content corresponding to theentropy-decoded index information.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of generating index information toidentify a content, entropy-encoding the index information, andtransferring the entropy-encoded index information.

An apparatus for processing a signal according to another embodiment ofthe present invention includes an information generating part generatingindex information to identify a content, an encoding partentropy-encoding the index information, and an information outputtingpart transferring the entropy-encoded index information.

A method of processing a signal according to another embodiment of thepresent invention includes the steps of obtaining a difference value andindex information, entropy-decoding the index information, identifyingan entropy table corresponding to the entropy-decoded index information,and entropy-decoding the difference value using the identified entropytable.

Subsequently, a reference value corresponding to a plurality of data andthe decoded difference value are used to obtain the data. In this case,the reference value may include a pilot reference value or a differencereference value.

The index information is entropy-decoded using an index dedicatedentropy table. And, the entropy table is classified according to a typeof each of a plurality of the data.

The data are parameters, and the method further includes the step ofreconstructing an audio signal using the parameters.

In case of entropy-decoding the difference value, 2D entropy decoding isperformed on the difference value using the entropy table.

Moreover, the method further includes the steps of obtaining thereference value and entropy-decoding the reference value using theentropy table dedicated to the reference value.

An apparatus for processing a signal according to another embodiment ofthe present invention includes an inputting part obtaining a differencevalue and index information, an index decoding part entropy-decoding theindex information, a table identifying part identifying an entropy tablecorresponding to the entropy-decoded index information, and a datadecoding part entropy-decoding the difference value using the identifiedentropy table.

The apparatus further includes a data obtaining part obtaining datausing a reference value corresponding to a plurality of data and thedecoded difference value.

A method of processing a signal according to a further embodiment of thepresent invention includes the steps of generating a difference valueusing a reference value corresponding to a plurality of data and thedata, entropy-encoding the difference value using an entropy table, andgenerating index information to identify the entropy table.

And, the method further includes the steps of entropy-encoding the indexinformation and transferring the entropy-encoded index information andthe difference value.

And, an apparatus for processing a signal according to a furtherembodiment of the present invention includes a value generating partgenerating a difference value using a reference value corresponding to aplurality of data and the data, a value encoding part entropy-encodingthe difference value using an entropy table, an information generatingpart generating index information to identify the entropy table, and anindex encoding part entropy-encoding the index information. And, theapparatus further includes an information outputting part transferringthe entropy-encoded index information and the difference value.

Data Structure

A data structure including various kinds of information associated withthe aforesaid data coding, grouping and entropy coding according to thepresent invention is explained as follows.

FIG. 23 is a hierarchical diagram of a data structure according to thepresent invention.

Referring to FIG. 23, a data structure according to the presentinvention includes a header 100 and a plurality off frames 101 and 102.Configuration information applied to the lower frames 101 and 102 incommon is included in the header 100. And, the configuration informationincludes grouping information utilized for the aforesaid grouping.

For instance, the grouping information includes a first time groupinginformation 100 a, a first frequency grouping information 100 b and achannel groping information 100 c.

Besides, the configuration information within the header 100 is called‘main configuration information’ and an information portion recorded inthe frame is called ‘payload’.

In particular, a case of applying the data structure of the presentinvention to audio spatial information is explained in the followingdescription for example.

First of all, the first time grouping information 100 a within theheader 100 becomes ‘bsFrameLength’ field that designates a number oftimeslots within a frame.

The first frequency grouping information 100 b becomes ‘bsFreqRes’ fieldthat designates a number of parameter bands within a frame.

The channel grouping information 100 c means ‘OttmodeLFE-bsOttBands’field and ‘bsTttDualmode-bsTttBandsLow’ field. The‘OttmodeLFE-bsOttBands’ field is the information designating a number ofparameter bands applied to LFE channel. And, the‘bsTttDualmode-bsTttBandsLow’ field is the information designating anumber of parameter bands of a low frequency band within a dual modehaving both low and high frequency bands. Ye, the‘bsTttDualmode-bsTttBandsLow’ field can be classified not as channelgrouping information but as frequency grouping information.

Each of the frames 101 and 102 includes a frame information (Frame Info)101 a applied to all groups within a frame in common and a plurality ofgroups 101 b and 101 c.

The frame information 101 a includes a time selection information 103 a,a second time grouping information 103 b and a second frequency groupinginformation 103 c. Besides, the frame information 101 a is called‘sub-configuration information’ applied to each frame.

In detail, a case of applying the data structure of the presentinvention to audio spatial information is explained in the followingdescription, for example.

The time selection information 103 a within the frame information 101 aincludes ‘bsNumParamset’ field, ‘bsParamslot’ field and ‘bsDataMode’filed.

The ‘bsNumParamset’ field is information indicating a number ofparameter sets existing within an entire frame.

And, the ‘bsParamslot’ field is information designating a position of atimeslot where a parameter set exists.

Moreover, the ‘bsDataMode’ field is information designating an encodingand decoding processing method of each parameter set.

For instance, in case of ‘bsDataMode=0’ (e.g., default mode) of aspecific parameter set, a decoding part replaces the correspondingparameter set by a default value.

In case of ‘bsDataMode=1’ (e.g., previous mode) of a specific parameterset, a decoding part maintains a decoding value of a previous parameterset.

In case of ‘bsDataMode=2’ (e.g., interpolation mode) of a specificparameter set, a decoding part calculates a corresponding parameter setby interpolation between parameter sets.

Finally, in case of ‘bsDataMode=3’ (e.g., read mode) of a specificparameter set, it means that coding data for a corresponding parameterset is transferred. So, a plurality of the groups 101 b and 101 c withina frame are groups configured with data transferred in case of‘bsDataMode=3’ (e.g., read mode). Hence, the encoding part decodes datawith reference to coding type information within each of the groups.

A signal processing method and apparatus using the ‘bsDataMode’ fieldaccording to one embodiment of the present invention are explained indetail as follows.

A method of processing a signal using the ‘bsDataMode’ field accordingto one embodiment of the present invention includes the steps ofobtaining mode information, obtaining a pilot reference valuecorresponding to a plurality of data and a pilot difference valuecorresponding to the pilot reference value according to data attributeindicated by the mode information, and obtaining the data using thepilot reference value and the pilot difference value.

In this case, the data are parameters, and the method further includesthe step of reconstructing an audio signal using the parameters.

If the mode information indicates a read mode, the pilot differencevalue is obtained.

The mode information further includes at least one of a default mode, aprevious mode and an interpolation mode.

And, the pilot difference value is obtained per group band.

Moreover, the signal processing method uses a first parameter (e.g.,dataset) to identify a number of the read modes and a second parameter(e.g., setidx) to obtain the pilot difference value based on the firstvariable.

An apparatus for processing a signal using the ‘bsDataMode’ fieldaccording to one embodiment of the present invention includes aninformation obtaining part obtaining mode information, a value obtainingpart obtaining a pilot reference value corresponding to a plurality ofdata and a pilot difference value corresponding to the pilot referencevalue according to data attribute indicated by the mode information, anda data obtaining part obtaining the data using the pilot reference valueand the pilot difference value.

And, the information obtaining part, the value obtaining part and thedata obtaining part are provided within the aforesaid data decoding part91 or 92.

A method of processing a signal using the ‘bsDataMode’ field accordingto another embodiment of the present invention includes the steps ofgenerating mode information indicating attribute of data, generating apilot difference value using a pilot reference value corresponding to aplurality of data and the data, and transferring the generateddifference value. And, the method further includes the step of encodingthe generated difference value.

An apparatus for processing a signal using the ‘bsDataMode’ fieldaccording to another embodiment of the present invention includes aninformation generating part generating mode information indicatingattribute of data, a value generating part generating a pilot differencevalue using a pilot reference value corresponding to a plurality of dataand the data, and an outputting part transferring the generateddifference value. And, the value generating part is provided within theaforesaid data encoding part 31 or 32.

The second time grouping information 103 b within the frame information101 a includes ‘bsDatapair’ field. The ‘bsDatapair’ field is informationthat designates a presence or non-presence of a pair between data setsdesignated by the ‘bsDataMode=3’. In particular, two data sets aregrouped into one group by the ‘bsDatapair’ field.

The second frequency grouping information within the frame information101 a includes ‘bsFreqResStride’ field. The ‘bsFreqResStride’ field isthe information to second-group the parameter bad first-grouped by the‘bsFreqRes’ field as the first frequency grouping information 100 b.Namely, a data band is generated by binding parameters amounting to astride designated by the ‘bsFreqResStride’ field. So, parameter valuesare given per the data band.

Each of the groups 101 b and 101 c includes data coding type information104 a, entropy coding type information 104 b, codeword 104 c and sidedata 104 d.

In detail, a case of applying the data structure of the presentinvention to audio spatial information is explained as follows, forexample.

First of all, the data coding type information 104 a within each of thegroups 101 b and 101 c includes ‘bsPCMCoding’ field, ‘bsPilotCoding’field, ‘bsDiffType’ field and ‘bdDifftimeDirection’ field.

The ‘bsPCMCoding’ field is information to identify whether data codingof the corresponding group is PCM scheme or DIFF scheme.

Only if the ‘bsPCMCoding’ field designates the PCM scheme, a presence ornon-presence of the PBC scheme is designated by the ‘bsPilotCoding’field.

The ‘bsDifftype’ field is information to designate a coding direction incase that DIFF scheme is applied. And, the ‘bsDiffType’ field designateseither ‘DF: DIFF-FREQ’ or ‘DT: DIFF-TIME’.

And, the ‘bsDiffTimeDirection’ field is information to designate whethera coding direction on a time axis is ‘FORWARD’ or ‘BACKWARD’ in casethat the ‘bsDiffType’ field is ‘DT’.

The entropy coding type information 104 b within each of the groups 101b and 101 c includes ‘bsCodingScheme’ field and ‘bsPairing’ field.

The ‘bsCodingScheme’ field is the information to designate whetherentropy coding is 1D or 2D.

And, the ‘bsPairing’ field is the information whether a direction forextracting two indexes is a frequency direction (FP: Frequency Pairing)or a time direction (TP: Time Pairing) in case that the ‘bsCodingScheme’field designates ‘2D’.

The codeword 104 c within each of the groups 101 b and 101 c includes‘bsCodeW’ field. And, the ‘bsCodeW’ field designates a codeword on atable applied for entropy coding. So, most of the aforesaid data becometargets of entropy coding. In this case, they are transferred by the‘bsCodeW’ field. For instance, a pilot reference value and LAV Indexvalue of PBC coding, which become targets of entropy coding, aretransferred by the ‘bsCodeW’ field.

The side data 104 d within each of the groups 101 b and 101 c includes‘bsLsb’ field and ‘bsSign’ field. In particular, the side data 104 dincludes other data, which are entropy-coded not to be transferred bythe ‘bsCodeW’ field, as well as the ‘bsLsb’ field and the ‘bsSign’field.

The ‘bsLsb’ field is a field applied to the aforesaid partial parameterand is the side information transferred only if a data type is ‘CPC’ andin case of non-coarse quantization.

And, the ‘bsSign’ field is the information to designate a sign of anindex extracted in case of applying 1D entropy coding.

Moreover, data transferred by PCM scheme are included in the side data104 d.

Features of the signal processing data structure according to thepresent invention are explained as follows.

First of all, a signal processing data structure according to thepresent invention includes a payload part having at least one of datacoding information including pilot coding information at least per aframe and entropy coding information and a header part having mainconfiguration information for the payload part.

The main configuration information includes a first time informationpart having time information for entire frames and a first frequencyinformation part having frequency information for the entire frames.

And, the main configuration information further includes a firstinternal grouping information part having information forinternal-grouping a random group including a plurality of data perframe.

The frame includes a first data part having at least one of the datacoding information and the entropy coding information and a frameinformation part having sub-configuration information for the first datapart.

The sub-configuration information includes a second time informationpart having time information for entire groups. And, thesub-configuration information further includes an external groupinginformation part having information for external grouping for a randomgroup including a plurality of data per the group. Moreover, thesub-configuration information further includes a second internalgrouping information part having information for internal-grouping therandom group including a plurality of the data.

Finally, the group includes the data coding information havinginformation for a data coding scheme, the entropy coding informationhaving information for an entropy coding scheme, a reference valuecorresponding to a plurality of data, and a second data part having adifference value generated using the reference value and the data.

Application to Audio Coding (MPEG Surround)

An example of unifying the aforesaid concepts and features of thepresent invention is explained as follows.

FIG. 24 is a block diagram of an apparatus for audio compression andrecovery according to one embodiment of the present invention.

Referring to FIG. 24, an apparatus for audio compression and recoveryaccording to one embodiment of the present invention includes an audiocompression part 105˜400 and an audio recovery part 500˜800.

The audio compression part 105˜400 includes a downmixing part 105, acore coding part 200, a spatial information coding part 300 and amultiplexing part 400.

And, the downmixing part 105 includes a channel downmixing part 110 anda spatial information generating part 120.

In the downmixing part 105, inputs of the channel downmixing part 110are an audio signal of N multi-channels X₁, X₂, . . . , X_(N)) and theaudio signal.

The channel downmixing part 110 outputs a signal downmixed into channelsof which number is smaller than that of channels of the inputs.

An output of the downmixing part 105 is downmixed into one or twochannels, a specific number of channels according to a separatedownmixing command, or a specific number of channels preset according tosystem implementation.

The core coding part 200 performs core coding on the output of thechannel downmixing part 110, i.e., the downmixed audio signal. In thiscase, the core coding is carried out in a manner of compressing an inputusing various transform schemes such as a discrete transform scheme andthe like.

The spatial information generating part 120 extracts spatial informationfrom the multi-channel audio signal. The spatial information generatingpart 120 then transfers the extracted spatial information to the spatialinformation coding part 300.

The spatial information coding part 300 performs data coding and entropycoding on the inputted spatial information. The spatial informationcoding part 300 performs at least one of PCM, PBC and DIFF. In somecases, the spatial information coding part 300 further performs entropycoding. A decoding scheme by a spatial information decoding part 700 canbe decided according to which data coding scheme is used by the spatialinformation coding part 300. And, the spatial information coding part300 will be explained in detail with reference to FIG. 25 later.

An output of the core coding part 200 and an output of the spatialinformation coding part 300 are inputted to the multiplexing part 400.

The multiplexing part 400 multiplexes the two inputs into a bitstreamand then transfers the bitstream to the audio recovery part 500 to 800.

The audio recovery part 500 to 800 includes a demultiplexing part 500, acore decoding part 600, a spatial information decoding part 700 and amulti-channel generating part 800.

The demultiplexing part 500 demultiplexes the received bitstream into anaudio part and a spatial information part. In this case, the audio partis a compressed audio signal and the spatial information part is acompressed spatial information.

The core decoding part 600 receives the compressed audio signal from thedemultiplexing part 500. The core decoding part 600 generates adownmixed audio signal by decoding the compressed audio signal.

The spatial information decoding part 700 receives the compressedspatial information from the demultiplexing part 500. The spatialinformation decoding part 700 generates the spatial information bydecoding the compressed spatial information.

In doing so, identification information indicating various groupinginformation and coding information included in the data structure shownin FIG. 23 is extracted from the received bitstream. A specific decodingscheme is selected from at least one or more decoding schemes accordingto the identification information. And, the spatial information isgenerated by decoding the spatial information according to the selecteddecoding scheme. In this case, the decoding scheme by the spatialinformation decoding part 700 can be decided according to what datacoding scheme is used by the spatial information coding part 300. And,the spatial information decoding part 700 is will be explained in detailwith reference to FIG. 26 later.

The multi-channel generating part 800 receives an output of the corecoding part 600 and an output of the spatial information decoding part160. The multi-channel generating part 800 generates an audio signal ofN multi-channels Y₁, Y₂, . . . , Y_(N) from the two received outputs.

Meanwhile, the audio compression part 105˜400 provides an identifierindicating what data coding scheme is used by the spatial informationcoding part 300 to the audio recovery part 500˜800. To prepare for theabove-explained case, the audio recovery part 500˜800 includes a meansfor parsing the identification information.

So, the spatial information decoding part 700 decides a decoding schemewith reference to the identification information provided by the audiocompression part 105˜400. Preferably, the means for parsing theidentification information indicating the coding scheme is provided tothe spatial information decoding part 700.

FIG. 25 is a detailed block diagram of a spatial information encodingpart according to one embodiment of the present invention, in whichspatial information is named a spatial parameter.

Referring to FIG. 25, a coding part according to one embodiment of thepresent invention includes a PCM coding part 310, a DIFF (differentialcoding) part 320 and a Huffman coding part 330. The Huffman coding part330 corresponds to one embodiment of performing the aforesaid entropycoding.

The PCM coding part 310 includes a grouped PCM coding part 311 and a PCBpart 312. The grouped PCM coding part 311 PCM-codes spatial parameters.In some cases, the grouped PCM coding part 311 is able to PCM-codesspatial parameters by a group part. And, the PBC part 312 performs theaforesaid PBC on spatial parameters.

The DIFF part 320 performs the aforesaid DIFF on spatial parameters.

In particular, in the present invention, one of the grouped PCM codingpart 311, the PBC part 312 and the DIFF part 320 selectively operatesfor coding of spatial parameters. And, its control means is notseparately shown in the drawing.

The PBC executed by the PBC part 312 has been explained in detail in theforegoing description, of which explanation will be omitted in thefollowing description.

For another example of PBC, PBC is once performed on spatial parameters.And, the PBC can be further performed N-times (N>1) on a result of thefirst PBC. In particular, the PBC is at least once carried out on apilot value or difference values as a result of performing the firstPBC. In some cases, it is preferable that the PBC is carried out on thedifference values only except the pilot value since the second PBC.

The DIFF part 320 includes a DIFF_FREQ coding part 321 performingDIFF_FREQ on a spatial parameter and DIFF_TIME coding parts 322 and 323performing DIFF_TIME on spatial parameters.

In the DIFF part 320, one selected from the group consisting of theDIFF_FREQ coding part 321 and the DIFF_TIME coding parts 322 and 323carries out the processing for an inputted spatial parameter.

In this case, the DIFF_TIME coding parts are classified into aDIFF_TIME_FORWARD part 322 performing DIFF_TIME_FORWARD on a spatialparameter and a DIFF_TIME_BACKWARD part 323 performingDIFF_TIME_BACKWARD on a spatial parameter.

In the DIFF_TIME coding parts 322 and 323, a selected one of theDIFF_TIME_FORWARD part 322 and the DIFF_TIME_BACKWARD 323 carries out adata coding process on an inputted spatial parameter. Besides, the DIFFcoding performed by each of the internal elements 321, 322 and 323 ofthe DIFF part 320 has been explained in detail in the foregoingdescription, of which explanation will be omitted in the followingdescription.

The Huffman coding part 330 performs Huffman coding on at least one ofan output of the PBC part 312 and an output of the DIF part 320.

The Huffman coding part 330 includes a 1-dimension Huffman coding part(hereinafter abbreviated HUFF_(—)1D part) 331 processing data to becoded and transmitted one by one and a 2-dimension Huffman coding part(hereinafter abbreviated HUFF_(—)2D parts 332 and 333 processing data tobe coded and transmitted by a unit of two combined data.

A selected one of the HUFF_(—)1D part 331 and the HUFF_(—)2D parts 332and 333 in the Huffman coding part 330 performs a Huffman codingprocessing on an input.

In this case, the HUFF_(—)2D parts 332 and 333 are classified into afrequency pair 2-Dimension Huffman coding part (hereinafter abbreviatedHUFF_(—)2D_FREQ_PAIR part) 332 performing Huffman coding on a data pairbound together based on a frequency and a time pair 2-Dimension Huffmancoding part (hereinafter abbreviated HUFF_(—)2D_TIME_PAIR part) 333performing Huffman coding on a data pair bound together based on a time.

In the HUFF_(—)2D parts 332 and 333, a selected one of theHUFF_(—)2D_FREQ_PAIR part 332 and the HUFF_(—)2D_TIME_PAIR part 333performs a Huffman coding processing on an input.

Huffman coding performed by each of the internal elements 331, 332 and333 of the Huffman coding part 330 will explained in detail in thefollowing description.

Thereafter, an output of the Huffman coding part 330 is multiplexed withan output of the grouped PCM coding part 311 to be transferred.

In a spatial information coding part according to the present invention,various kinds of identification information generated from data codingand entropy coding are inserted into a transport bitstream. And, thetransport bitstream is transferred to a spatial information decodingpart shown in FIG. 26.

FIG. 26 is a detailed block diagram of a spatial information decodingpart according to one embodiment of the present invention.

Referring to FIG. 26, a spatial information decoding part receives atransport bitstream including spatial information and then generates thespatial information by decoding the received transport bitstream.

A spatial information decoding part 700 includes an identifierextracting (flags parsing part) 710, a PCM decoding part 720, a Huffmandecoding part 730 and a differential decoding part 740.

The identifier parsing part 710 of the spatial information decoding partextracts various identifiers from a transport bitstream and then parsesthe extracted identifiers. This means that various kinds of theinformations mentioned in the foregoing description of FIG. 23 areextracted.

The spatial information decoding part is able to know what kind ofcoding scheme is used for a spatial parameter using an output of theidentifier parsing part 710 and then decides a decoding schemecorresponding to the recognized coding scheme. Besides, the execution ofthe identifier parsing part 710 can be performed by the aforesaiddemultiplexing part 500 as well.

The PCM decoding part 720 includes a grouped PCM decoding part 721 and apilot based decoding part 722.

The grouped PCM decoding part 721 generates spatial parameters byperforming PCM decoding on a transport bitstream. In some cases, thegrouped PCM decoding part 721 generates spatial parameters of a grouppart by decoding a transport bitstream.

The pilot based decoding part 722 generates spatial parameter values byperforming pilot based decoding on an output of the Huffman decodingpart 730. This corresponds to a case that a pilot value is included inan output of the Huffman decoding part 730. For separate example, thepilot based decoding part 722 is able to include a pilot extracting part(not shown in the drawing) to directly extract a pilot value from atransport bitstream. So, spatial parameter values are generated usingthe pilot value extracted by the pilot extracting part and differencevalues that are the outputs of the Huffman decoding part 730.

The Huffman decoding part 730 performs Huffman decoding on a transportbitstream. The Huffman decoding part 730 includes a 1-Dimension Huffmandecoding part (hereinafter abbreviated HUFF_(—)1D decoding part) 731outputting a data value one by one by performing 1-Dimension Huffmandecoding on a transport bitstream and 2-Dimension Huffman decoding parts(hereinafter abbreviated HUFF_(—)2D decoding parts) 732 and 733outputting a pair of data values each by performing 2-Dimension Huffmandecoding on a transport bitstream.

The identifier parsing part 710 extracts an identifier (e.g.,‘bsCodingScheme’) indicating whether a Huffman decoding scheme indicatesHUFF_(—)1D or HUFF_(—)2D from a transport bitstream and then recognizesthe used Huffman coding scheme by parsing the extracted identifier. So,either HUFF_(—)1D or HUFF_(—)2D decoding corresponding to each case isdecided as a Huffman decoding scheme.

The HUFF_(—)1D decoding part 731 performs HUFF_(—)1D decoding and eachof the HUFF_(—)2D decoding parts 732 and 733 performs HUF_(—)2Ddecoding.

In case that the Huffman coding scheme is HUFF_(—)2D in a transport bitstream, the identifier parsing part 710 further extracts an identifier(e.g., ‘bsParsing’) indicating whether the HUFF_(—)2D scheme isHUFF_(—)2D_FREQ_PAIR or HUFF_(—)2D_TIME_PAIR and then parses theextracted identifier. So, the identifier parsing part 710 is able torecognize whether two data configuring one pair are bound together basedon frequency or time. And, one of frequency pair 2-Dimension Huffmandecoding (hereinafter abbreviated HUFF_(—)2D_FREQ_PAIR decoding) andtime pair 2-Dimension Huffman decoding (hereinafter abbreviatedHUFF_(—)2D_TIME_PAIR decoding) corresponding to the respective cases isdecided as the Huffman decoding scheme.

In the HUFF_(—)2D decoding parts 732 and 733, the HUFF_(—)2D_FREQ_PAIRpart 732 performs HUFF_(—)2D_FREQ_PAIR decoding and theHUFF_(—)2D_TIME_PAIR part 733 performs HUFF_(—)2D_FREQ_TIME decoding.

An output of the Huffman decoding part 730 is transferred to the pilotbased decoding part 722 or the differential decoding part 740 based onan output of the identifier parsing part 710.

The differential decoding part 740 generates spatial parameter values byperforming differential decoding on an output of the Huffman decodingpart 730.

The identifier parsing part 710 extracts an identifier (e.g.,‘bsDiffType’) indicating whether a DIFF scheme is DIF_FREQ or DIF_TIMEfrom a transport bit stream from a transport bitstream and thenrecognizes the used DIFF scheme by parsing the extracted identifier. So,one of the DIFF_FREQ decoding and DIFF_TIME decoding corresponding tothe respective cases is decided as a differential decoding scheme.

The DIFF_FREQ decoding part 741 performs DIFF_FREQ decoding and each ofthe DIFF_TIME decoding parts 742 and 743 performs DIF_TIME decoding.

In case that the DIFF scheme is DIFF_TIME, the identifier parsing part710 further extracts an identifier (e.g., ‘bsDiffTimeDirection’)indicating whether the DIFF_TIME is DIFF_TIME_FORWARD orDIFF_TIME_BACKWARD from a transport bitstream and then parses theextracted identifier.

So, it is able to recognize whether an output of the Huffman decodingpart 730 is a difference value between current data and former data or adifference value between the current data and next data. One ofDIFF_TIME_FORWARD decoding and DIFF_TIME_BACKWARD decoding correspondingto the respective cases is decided as a DIFF_TIME scheme.

In the DIFF_TIME decoding parts 742 and 743, the DIFF_TIME_FORWARD part742 performs DIFF_TIME_FORWARD decoding and the DIFF_TIME BACKWARD part743 performs DIFF_TIME_BACKWARD decoding.

A procedure for deciding a Huffman decoding scheme and a data decodingscheme based on an output of the identifier parsing part 710 in thespatial information decoding part is explained as follows.

For instance, the identifier parsing part 710 reads a first identifier(e.g., ‘bsPCMCoding’) indicating which one of PCM and DIFF is used incoding a spatial parameter.

If the first identifier corresponds to a value indicating PCM, theidentifier parsing part 710 further reads a second identifier (e.g.,‘bsPilotCoding’) indicating which one of PCM and PBC is used for codingof a spatial parameter.

If the second identifier corresponds to a value indicating PBC, thespatial information decoding part performs decoding corresponding to thePBC.

If the second identifier corresponds to a value indicating PCM, thespatial information decoding part performs decoding corresponding to thePCM.

On the other hand, if the first identifier corresponds to a valueindicating DIFF, the spatial information decoding part performs adecoding processing that corresponds to the DIFF.

MODE FOR INVENTION

Accordingly, various embodiments of the present invention are explainedtogether with the aforesaid embodiments of the best mode.

INDUSTRIAL APPLICABILITY

Accordingly, the grouping, data coding and entropy coding of the presentinvention are applicable to various fields and products.

And, the present invention is applicable to a medium that stores data towhich at least one feature of the present invention is applied.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents.

1. A method for processing a signal, comprising: obtaining a pilotreference value corresponding to a plurality of data and a pilotdifference value corresponding to the pilot reference value; andobtaining the data using the pilot reference value and the pilotdifference value.
 2. The method of claim 1, further comprising decodingat least one of the pilot reference value and the pilot differencevalue.
 3. The method of claim 1, wherein the data includes parametersand wherein the method further comprises reconstructing an audio signalusing the obtained parameters.
 4. The method of claim 3, wherein theparameters comprise at least one of channel level difference (CLD),interchannel coherence (ICC), channel prediction coefficient (CPC) andarbitrary downmix gain (ADG).
 5. The method of claim 1, wherein thepilot reference value comprises one of an average value, an intermediatevalue, a most frequently used value and a default value of the pluralityof the data.
 6. The method of claim 1, wherein the pilot reference valueis one value extracted from a table.
 7. The method of claim 1, furthercomprising selecting the data having highest encoding efficiency as apilot reference value after the pilot reference value has been set toeach of the plurality of the data.
 8. (canceled)
 9. A method forprocessing a signal, comprising: generating a pilot difference valueusing a pilot reference value corresponding to a plurality of the dataand the data; and transferring the generated pilot difference value. 10.An apparatus for processing a signal, comprising: a value generatingpart generating a pilot difference value using a pilot reference valuecorresponding to the plurality of data and the data; and an outputtingpart transferring the generated pilot difference value.
 11. An apparatusfor processing a signal, comprising: a value obtaining part obtaining apilot reference value corresponding to a plurality of data and a pilotdifference value corresponding to the pilot reference value; and, a dataobtaining part obtaining the data using the pilot reference value andthe pilot difference value.
 12. The apparatus of claim 11, wherein thedata obtaining part decodes at least one of the pilot difference valueand the pilot reference value.
 13. The apparatus of claim 11, whereinthe data includes parameters and wherein the apparatus further comprisesa multi-channel generation part reconstructing an audio signal using theobtained parameters.
 14. The apparatus of claim 13, wherein theparameters comprise at least one of channel level difference (CLD),interchannel coherence (ICC), channel prediction coefficient (CPC) andarbitrary downmix gain (ADG).
 15. The apparatus of claim 11, wherein thepilot reference value comprises one of an average value, an intermediatevalue, a most frequently used value and a default value of the pluralityof the data.
 16. The apparatus of claim 11, wherein the pilot referencevalue is one value extracted from a table.